diff --git a/packages/components/select/index.ts b/packages/components/select/index.ts
index 7cab0e4485..e89e49e2bc 100644
--- a/packages/components/select/index.ts
+++ b/packages/components/select/index.ts
@@ -1,8 +1,8 @@
 import { withInstall, withNoopInstall } from '@element-plus/utils'
-
 import Select from './src/select.vue'
 import Option from './src/option.vue'
 import OptionGroup from './src/option-group.vue'
+
 import type { SFCWithInstall } from '@element-plus/utils'
 
 export const ElSelect: SFCWithInstall<typeof Select> & {
@@ -18,3 +18,10 @@ export const ElOptionGroup: SFCWithInstall<typeof OptionGroup> =
   withNoopInstall(OptionGroup)
 
 export * from './src/token'
+export * from './src/select'
+
+export type {
+  SelectContext,
+  OptionPublicInstance as SelectOptionProxy,
+  OptionBasic,
+} from './src/type'
diff --git a/packages/components/select/src/option-group.vue b/packages/components/select/src/option-group.vue
index db4e653998..76e5411d69 100644
--- a/packages/components/select/src/option-group.vue
+++ b/packages/components/select/src/option-group.vue
@@ -10,11 +10,11 @@
 </template>
 
 <script lang="ts">
-// @ts-nocheck
 import {
   computed,
   defineComponent,
   getCurrentInstance,
+  isVNode,
   onMounted,
   provide,
   reactive,
@@ -22,10 +22,13 @@ import {
   toRefs,
 } from 'vue'
 import { useMutationObserver } from '@vueuse/core'
-import { ensureArray } from '@element-plus/utils'
+import { ensureArray, isArray } from '@element-plus/utils'
 import { useNamespace } from '@element-plus/hooks'
 import { selectGroupKey } from './token'
 
+import type { Component, VNode, VNodeArrayChildren } from 'vue'
+import type { OptionInternalInstance, OptionPublicInstance } from './type'
+
 export default defineComponent({
   name: 'ElOptionGroup',
   componentName: 'ElOptionGroup',
@@ -42,9 +45,9 @@ export default defineComponent({
   },
   setup(props) {
     const ns = useNamespace('select')
-    const groupRef = ref(null)
-    const instance = getCurrentInstance()
-    const children = ref([])
+    const groupRef = ref<HTMLElement>()
+    const instance = getCurrentInstance()!
+    const children = ref<OptionPublicInstance[]>([])
 
     provide(
       selectGroupKey,
@@ -57,18 +60,22 @@ export default defineComponent({
       children.value.some((option) => option.visible === true)
     )
 
-    const isOption = (node) =>
-      node.type?.name === 'ElOption' && !!node.component?.proxy
+    const isOption = (
+      node: VNode
+    ): node is VNode & { component: OptionInternalInstance } =>
+      (node.type as Component).name === 'ElOption' && !!node.component?.proxy
 
     // get all instances of options
-    const flattedChildren = (node) => {
-      const Nodes = ensureArray(node)
-      const children = []
+    const flattedChildren = (node: VNode | VNodeArrayChildren) => {
+      const nodes = ensureArray(node) as VNode[] | VNodeArrayChildren
+      const children: OptionPublicInstance[] = []
+
+      nodes.forEach((child) => {
+        if (!isVNode(child)) return
 
-      Nodes.forEach((child) => {
         if (isOption(child)) {
           children.push(child.component.proxy)
-        } else if (child.children?.length) {
+        } else if (isArray(child.children) && child.children.length) {
           children.push(...flattedChildren(child.children))
         } else if (child.component?.subTree) {
           children.push(...flattedChildren(child.component.subTree))
diff --git a/packages/components/select/src/option.ts b/packages/components/select/src/option.ts
new file mode 100644
index 0000000000..6a03a32e24
--- /dev/null
+++ b/packages/components/select/src/option.ts
@@ -0,0 +1,23 @@
+import { buildProps } from '@element-plus/utils'
+
+export const COMPONENT_NAME = 'ElOption'
+export const optionProps = buildProps({
+  /**
+   * @description value of option
+   */
+  value: {
+    type: [String, Number, Boolean, Object],
+    required: true as const,
+  },
+  /**
+   * @description label of option, same as `value` if omitted
+   */
+  label: {
+    type: [String, Number],
+  },
+  created: Boolean,
+  /**
+   * @description whether option is disabled
+   */
+  disabled: Boolean,
+})
diff --git a/packages/components/select/src/option.vue b/packages/components/select/src/option.vue
index 728a2f90c9..4628671deb 100644
--- a/packages/components/select/src/option.vue
+++ b/packages/components/select/src/option.vue
@@ -16,7 +16,6 @@
 </template>
 
 <script lang="ts">
-// @ts-nocheck
 import {
   computed,
   defineComponent,
@@ -29,30 +28,15 @@ import {
 } from 'vue'
 import { useId, useNamespace } from '@element-plus/hooks'
 import { useOption } from './useOption'
-import type { SelectOptionProxy } from './token'
+import { COMPONENT_NAME, optionProps } from './option'
+
+import type { OptionExposed, OptionInternalInstance, OptionStates } from './type'
 
 export default defineComponent({
-  name: 'ElOption',
-  componentName: 'ElOption',
+  name: COMPONENT_NAME,
+  componentName: COMPONENT_NAME,
 
-  props: {
-    /**
-     * @description value of option
-     */
-    value: {
-      required: true,
-      type: [String, Number, Boolean, Object],
-    },
-    /**
-     * @description label of option, same as `value` if omitted
-     */
-    label: [String, Number],
-    created: Boolean,
-    /**
-     * @description whether option is disabled
-     */
-    disabled: Boolean,
-  },
+  props: optionProps,
 
   setup(props) {
     const ns = useNamespace('select')
@@ -65,7 +49,7 @@ export default defineComponent({
       ns.is('hovering', unref(hover)),
     ])
 
-    const states = reactive({
+    const states = reactive<OptionStates>({
       index: -1,
       groupDisabled: false,
       visible: true,
@@ -83,7 +67,7 @@ export default defineComponent({
 
     const { visible, hover } = toRefs(states)
 
-    const vm = getCurrentInstance().proxy as unknown as SelectOptionProxy
+    const vm = (getCurrentInstance()! as OptionInternalInstance).proxy
 
     select.onOptionCreate(vm)
 
@@ -116,13 +100,14 @@ export default defineComponent({
       itemSelected,
       isDisabled,
       select,
-      hoverItem,
-      updateOption,
       visible,
       hover,
-      selectOptionClick,
       states,
-    }
+
+      hoverItem,
+      updateOption,
+      selectOptionClick,
+    } satisfies OptionExposed
   },
 })
 </script>
diff --git a/packages/components/select/src/options.ts b/packages/components/select/src/options.ts
index 70dfd73b96..4d7052040c 100644
--- a/packages/components/select/src/options.ts
+++ b/packages/components/select/src/options.ts
@@ -2,17 +2,19 @@ import { defineComponent, inject } from 'vue'
 import { isEqual } from 'lodash-unified'
 import { isArray, isFunction, isString } from '@element-plus/utils'
 import { selectKey } from './token'
+
 import type { Component, VNode, VNodeNormalizedChildren } from 'vue'
+import type { OptionValue } from './type'
 
 export default defineComponent({
   name: 'ElOptions',
   setup(_, { slots }) {
     const select = inject(selectKey)
-    let cachedValueList: any[] = []
+    let cachedValueList: OptionValue[] = []
 
     return () => {
       const children = slots.default?.()!
-      const valueList: any[] = []
+      const valueList: OptionValue[] = []
 
       function filterOptions(children?: VNodeNormalizedChildren) {
         if (!isArray(children)) return
diff --git a/packages/components/select/src/select.ts b/packages/components/select/src/select.ts
index 6b53720b09..6bc9cb0599 100644
--- a/packages/components/select/src/select.ts
+++ b/packages/components/select/src/select.ts
@@ -1,18 +1,29 @@
 import { placements } from '@popperjs/core'
+import { scrollbarEmits } from 'element-plus'
 import {
   useAriaProps,
   useEmptyValuesProps,
   useSizeProp,
 } from '@element-plus/hooks'
-import { buildProps, definePropType, iconPropType } from '@element-plus/utils'
+import {
+  EmitFn,
+  buildProps,
+  definePropType,
+  iconPropType,
+} from '@element-plus/utils'
 import { useTooltipContentProps } from '@element-plus/components/tooltip'
 import { ArrowDown, CircleClose } from '@element-plus/icons-vue'
 import { tagProps } from '@element-plus/components/tag'
+import { CHANGE_EVENT, UPDATE_MODEL_EVENT } from '@element-plus/constants'
+
+import type { ExtractPropTypes } from 'vue'
+import type Select from './select.vue'
 import type {
   Options,
   Placement,
   PopperEffect,
 } from '@element-plus/components/popper'
+import type { OptionValue } from './type'
 
 export const SelectProps = buildProps({
   /**
@@ -27,7 +38,13 @@ export const SelectProps = buildProps({
    * @description binding value
    */
   modelValue: {
-    type: [Array, String, Number, Boolean, Object],
+    type: definePropType<OptionValue | OptionValue[]>([
+      Array,
+      String,
+      Number,
+      Boolean,
+      Object,
+    ]),
     default: undefined,
   },
   /**
@@ -252,3 +269,19 @@ export const SelectProps = buildProps({
   ...useEmptyValuesProps,
   ...useAriaProps(['ariaLabel']),
 })
+/* eslint-disable @typescript-eslint/no-unused-vars */
+export const selectEmits = {
+  [UPDATE_MODEL_EVENT]: (val: ISelectProps['modelValue']) => true,
+  [CHANGE_EVENT]: (val: ISelectProps['modelValue']) => true,
+  'popup-scroll': scrollbarEmits.scroll,
+  'remove-tag': (val: unknown) => true,
+  'visible-change': (visible: boolean) => true,
+  focus: (evt: FocusEvent) => evt instanceof FocusEvent,
+  blur: (evt: FocusEvent) => evt instanceof FocusEvent,
+  clear: () => true,
+}
+/* eslint-enable @typescript-eslint/no-unused-vars */
+
+export type ISelectProps = ExtractPropTypes<typeof SelectProps>
+export type SelectEmits = EmitFn<typeof selectEmits>
+export type SelectInstance = InstanceType<typeof Select> & unknown
diff --git a/packages/components/select/src/select.vue b/packages/components/select/src/select.vue
index 802c00e69d..1595319fab 100644
--- a/packages/components/select/src/select.vue
+++ b/packages/components/select/src/select.vue
@@ -314,9 +314,9 @@ import ElSelectMenu from './select-dropdown.vue'
 import { useSelect } from './useSelect'
 import { selectKey } from './token'
 import ElOptions from './options'
-
 import { SelectProps } from './select'
-import type { SelectContext } from './token'
+
+import type { SelectContext } from './type'
 
 const COMPONENT_NAME = 'ElSelect'
 export default defineComponent({
@@ -370,13 +370,13 @@ export default defineComponent({
       reactive({
         props: _props,
         states: API.states,
+        selectRef: API.selectRef,
         optionsArray: API.optionsArray,
+        setSelected: API.setSelected,
         handleOptionSelect: API.handleOptionSelect,
         onOptionCreate: API.onOptionCreate,
         onOptionDestroy: API.onOptionDestroy,
-        selectRef: API.selectRef,
-        setSelected: API.setSelected,
-      }) as unknown as SelectContext
+      }) satisfies SelectContext
     )
 
     const selectedLabel = computed(() => {
diff --git a/packages/components/select/src/token.ts b/packages/components/select/src/token.ts
index b976746ef9..df24d0ee84 100644
--- a/packages/components/select/src/token.ts
+++ b/packages/components/select/src/token.ts
@@ -1,45 +1,8 @@
-import type { ExtractPropTypes, InjectionKey } from 'vue'
-import type { SelectProps } from './select'
-
-interface SelectGroupContext {
-  disabled: boolean
-}
-
-export interface SelectContext {
-  props: ExtractPropTypes<typeof SelectProps>
-  states: any
-  expanded: boolean
-  selectRef: HTMLElement
-  optionsArray: any[]
-  setSelected(): void
-  onOptionCreate(vm: SelectOptionProxy): void
-  onOptionDestroy(
-    key: number | string | Record<string, string>,
-    vm: SelectOptionProxy
-  ): void
-  handleOptionSelect(vm: SelectOptionProxy): void
-}
+import type { InjectionKey } from 'vue'
+import type { SelectContext, SelectGroupContext } from './type'
 
 // For individual build sharing injection key, we had to make `Symbol` to string
 export const selectGroupKey: InjectionKey<SelectGroupContext> =
   Symbol('ElSelectGroup')
 
 export const selectKey: InjectionKey<SelectContext> = Symbol('ElSelect')
-
-export interface SelectOptionProxy {
-  value: string | number | Record<string, string>
-  label: string | number
-  created: boolean
-  disabled: boolean
-  currentLabel: string
-  itemSelected: boolean
-  isDisabled: boolean
-  select: SelectContext
-  hoverItem: () => void
-  updateOption: (query: string) => void
-  visible: boolean
-  hover: boolean
-  selectOptionClick: () => void
-}
-
-export type ISelectProps = ExtractPropTypes<typeof SelectProps>
diff --git a/packages/components/select/src/type.ts b/packages/components/select/src/type.ts
new file mode 100644
index 0000000000..37dfc4b9b3
--- /dev/null
+++ b/packages/components/select/src/type.ts
@@ -0,0 +1,72 @@
+import type {
+  ComponentInternalInstance,
+  ComponentPublicInstance,
+  ComputedRef,
+  ExtractPropTypes,
+  Ref,
+} from 'vue'
+import type { ISelectProps } from './select'
+import type { optionProps } from './option'
+export interface SelectGroupContext {
+  disabled: boolean
+}
+export interface SelectContext {
+  props: ISelectProps
+  states: SelectStates
+  selectRef: HTMLElement | undefined
+  optionsArray: OptionPublicInstance[]
+  setSelected(): void
+  onOptionCreate(vm: OptionPublicInstance): void
+  onOptionDestroy(key: OptionValue, vm: OptionPublicInstance): void
+  handleOptionSelect(vm: OptionPublicInstance): void
+}
+export type SelectStates = {
+  inputValue: string
+  options: Map<OptionValue, OptionPublicInstance>
+  cachedOptions: Map<OptionValue, OptionPublicInstance>
+  optionValues: OptionValue[]
+  selected: OptionBasic[]
+  hoveringIndex: number
+  inputHovering: boolean
+  selectionWidth: number
+  collapseItemWidth: number
+  previousQuery: string | null
+  selectedLabel: string
+  menuVisibleOnFocus: boolean
+  isBeforeHide: boolean
+}
+export type OptionProps = ExtractPropTypes<typeof optionProps>
+export interface OptionStates {
+  index: number
+  groupDisabled: boolean
+  visible: boolean
+  hover: boolean
+}
+export interface OptionExposed {
+  ns: unknown
+  id: unknown
+  containerKls: unknown
+  currentLabel: ComputedRef<string | number | boolean>
+  itemSelected: ComputedRef<boolean>
+  isDisabled: ComputedRef<boolean>
+  visible: Ref<boolean>
+  hover: Ref<boolean>
+  states: OptionStates
+  select: SelectContext
+  hoverItem: () => void
+  updateOption: (query: string) => void
+  selectOptionClick: () => void
+}
+export type OptionPublicInstance = ComponentPublicInstance<
+  OptionProps,
+  OptionExposed
+>
+export type OptionInternalInstance = ComponentInternalInstance & {
+  proxy: OptionPublicInstance
+}
+export type OptionValue = OptionProps['value']
+export type OptionBasic = {
+  value: OptionValue
+  currentLabel: OptionPublicInstance['currentLabel']
+  isDisabled?: OptionPublicInstance['isDisabled']
+}
diff --git a/packages/components/select/src/useOption.ts b/packages/components/select/src/useOption.ts
index 1c7180ed1c..e7d321d76b 100644
--- a/packages/components/select/src/useOption.ts
+++ b/packages/components/select/src/useOption.ts
@@ -1,12 +1,22 @@
-// @ts-nocheck
 import { computed, getCurrentInstance, inject, toRaw, watch } from 'vue'
 import { get, isEqual } from 'lodash-unified'
-import { ensureArray, escapeStringRegexp, isObject } from '@element-plus/utils'
+import {
+  ensureArray,
+  escapeStringRegexp,
+  isObject,
+  throwError,
+} from '@element-plus/utils'
 import { selectGroupKey, selectKey } from './token'
+import { COMPONENT_NAME } from './option'
 
-export function useOption(props, states) {
+import type { OptionInternalInstance, OptionProps, OptionStates } from './type'
+
+export function useOption(props: OptionProps, states: OptionStates) {
   // inject
   const select = inject(selectKey)
+  if (!select) {
+    throwError(COMPONENT_NAME, 'usage: <el-select><el-option /></el-select/>')
+  }
   const selectGroup = inject(selectGroupKey, { disabled: false })
 
   // computed
@@ -39,9 +49,8 @@ export function useOption(props, states) {
     return props.disabled || states.groupDisabled || limitReached.value
   })
 
-  const instance = getCurrentInstance()
-
-  const contains = (arr = [], target) => {
+  const instance = getCurrentInstance()! as OptionInternalInstance
+  const contains = <T>(arr: T[] = [], target: T) => {
     if (!isObject(props.value)) {
       return arr && arr.includes(target)
     } else {
@@ -63,7 +72,7 @@ export function useOption(props, states) {
 
   const updateOption = (query: string) => {
     const regexp = new RegExp(escapeStringRegexp(query), 'i')
-    states.visible = regexp.test(currentLabel.value) || props.created
+    states.visible = regexp.test(String(currentLabel.value)) || props.created
   }
 
   watch(
diff --git a/packages/components/select/src/useSelect.ts b/packages/components/select/src/useSelect.ts
index ea0dde067f..f86a8d197d 100644
--- a/packages/components/select/src/useSelect.ts
+++ b/packages/components/select/src/useSelect.ts
@@ -1,5 +1,5 @@
-// @ts-nocheck
 import {
+  Component,
   computed,
   nextTick,
   onMounted,
@@ -49,20 +49,22 @@ import {
 } from '@element-plus/components/form'
 
 import type { TooltipInstance } from '@element-plus/components/tooltip'
-import type { ISelectProps, SelectOptionProxy } from './token'
+import type { ScrollbarInstance } from '@element-plus/components/scrollbar'
+import type { ISelectProps, SelectEmits } from './select'
+import type { OptionPublicInstance, OptionValue, SelectStates } from './type'
 
-export const useSelect = (props: ISelectProps, emit) => {
+export const useSelect = (props: ISelectProps, emit: SelectEmits) => {
   const { t } = useLocale()
   const contentId = useId()
   const nsSelect = useNamespace('select')
   const nsInput = useNamespace('input')
 
-  const states = reactive({
+  const states = reactive<SelectStates>({
     inputValue: '',
     options: new Map(),
     cachedOptions: new Map(),
-    optionValues: [] as any[], // sorted value of options
-    selected: [] as any[],
+    optionValues: [], // sorted value of options
+    selected: [],
     selectionWidth: 0,
     collapseItemWidth: 0,
     selectedLabel: '',
@@ -74,19 +76,17 @@ export const useSelect = (props: ISelectProps, emit) => {
   })
 
   // template refs
-  const selectRef = ref<HTMLElement>(null)
-  const selectionRef = ref<HTMLElement>(null)
-  const tooltipRef = ref<TooltipInstance | null>(null)
-  const tagTooltipRef = ref<TooltipInstance | null>(null)
-  const inputRef = ref<HTMLInputElement | null>(null)
-  const prefixRef = ref<HTMLElement>(null)
-  const suffixRef = ref<HTMLElement>(null)
-  const menuRef = ref<HTMLElement>(null)
-  const tagMenuRef = ref<HTMLElement>(null)
-  const collapseItemRef = ref<HTMLElement>(null)
-  const scrollbarRef = ref<{
-    handleScroll: () => void
-  } | null>(null)
+  const selectRef = ref<HTMLElement>()
+  const selectionRef = ref<HTMLElement>()
+  const tooltipRef = ref<TooltipInstance>()
+  const tagTooltipRef = ref<TooltipInstance>()
+  const inputRef = ref<HTMLInputElement>()
+  const prefixRef = ref<HTMLElement>()
+  const suffixRef = ref<HTMLElement>()
+  const menuRef = ref<HTMLElement>()
+  const tagMenuRef = ref<HTMLElement>()
+  const collapseItemRef = ref<HTMLElement>()
+  const scrollbarRef = ref<ScrollbarInstance>()
 
   const {
     isComposing,
@@ -153,12 +153,14 @@ export const useSelect = (props: ISelectProps, emit) => {
       : props.suffixIcon
   )
   const iconReverse = computed(() =>
-    nsSelect.is('reverse', iconComponent.value && expanded.value)
+    nsSelect.is('reverse', !!(iconComponent.value && expanded.value))
   )
 
   const validateState = computed(() => formItem?.validateState || '')
   const validateIcon = computed(
-    () => ValidateComponentsMap[validateState.value]
+    () =>
+      validateState.value &&
+      (ValidateComponentsMap[validateState.value] as Component)
   )
 
   const debounce = computed(() => (props.remote ? 300 : 0))
@@ -192,7 +194,7 @@ export const useSelect = (props: ISelectProps, emit) => {
 
   const optionsArray = computed(() => {
     const list = Array.from(states.options.values())
-    const newList = []
+    const newList: OptionPublicInstance[] = []
     states.optionValues.forEach((item) => {
       const index = list.findIndex((i) => i.value === item)
       if (index > -1) {
@@ -402,7 +404,7 @@ export const useSelect = (props: ISelectProps, emit) => {
     } else {
       states.selectedLabel = ''
     }
-    const result: any[] = []
+    const result: SelectStates['selected'] = []
     if (!isUndefined(props.modelValue)) {
       ensureArray(props.modelValue).forEach((value) => {
         result.push(getOption(value))
@@ -411,7 +413,7 @@ export const useSelect = (props: ISelectProps, emit) => {
     states.selected = result
   }
 
-  const getOption = (value) => {
+  const getOption = (value: OptionValue) => {
     let option
     const isObjectValue = isPlainObject(value)
 
@@ -449,12 +451,12 @@ export const useSelect = (props: ISelectProps, emit) => {
   }
 
   const resetSelectionWidth = () => {
-    states.selectionWidth = selectionRef.value.getBoundingClientRect().width
+    states.selectionWidth = selectionRef.value!.getBoundingClientRect().width
   }
 
   const resetCollapseItemWidth = () => {
     states.collapseItemWidth =
-      collapseItemRef.value.getBoundingClientRect().width
+      collapseItemRef.value!.getBoundingClientRect().width
   }
 
   const updateTooltip = () => {
@@ -472,8 +474,8 @@ export const useSelect = (props: ISelectProps, emit) => {
     handleQueryChange(states.inputValue)
   }
 
-  const onInput = (event) => {
-    states.inputValue = event.target.value
+  const onInput = (event: Event) => {
+    states.inputValue = (event.target as HTMLInputElement).value
     if (props.remote) {
       debouncedOnInputChange()
     } else {
@@ -485,22 +487,22 @@ export const useSelect = (props: ISelectProps, emit) => {
     onInputChange()
   }, debounce.value)
 
-  const emitChange = (val) => {
+  const emitChange = (val: OptionValue | OptionValue[]) => {
     if (!isEqual(props.modelValue, val)) {
       emit(CHANGE_EVENT, val)
     }
   }
 
-  const getLastNotDisabledIndex = (value) =>
+  const getLastNotDisabledIndex = (value: OptionValue[]) =>
     findLastIndex(value, (it) => {
       const option = states.cachedOptions.get(it)
       return option && !option.disabled && !option.states.groupDisabled
     })
 
-  const deletePrevTag = (e) => {
+  const deletePrevTag = (e: KeyboardEvent) => {
     if (!props.multiple) return
     if (e.code === EVENT_CODE.delete) return
-    if (e.target.value.length <= 0) {
+    if ((e.target as HTMLInputElement).value.length <= 0) {
       const value = ensureArray(props.modelValue).slice()
       const lastNotDisabledIndex = getLastNotDisabledIndex(value)
       if (lastNotDisabledIndex < 0) return
@@ -512,7 +514,10 @@ export const useSelect = (props: ISelectProps, emit) => {
     }
   }
 
-  const deleteTag = (event, tag) => {
+  const deleteTag = (
+    event: MouseEvent,
+    tag: OptionPublicInstance | SelectStates['selected'][0]
+  ) => {
     const index = states.selected.indexOf(tag)
     if (index > -1 && !selectDisabled.value) {
       const value = ensureArray(props.modelValue).slice()
@@ -525,9 +530,9 @@ export const useSelect = (props: ISelectProps, emit) => {
     focus()
   }
 
-  const deleteSelected = (event) => {
+  const deleteSelected = (event: Event) => {
     event.stopPropagation()
-    const value: string | any[] = props.multiple ? [] : valueOnClear.value
+    const value = props.multiple ? [] : valueOnClear.value
     if (props.multiple) {
       for (const item of states.selected) {
         if (item.isDisabled) value.push(item.value)
@@ -541,7 +546,7 @@ export const useSelect = (props: ISelectProps, emit) => {
     focus()
   }
 
-  const handleOptionSelect = (option) => {
+  const handleOptionSelect = (option: OptionPublicInstance) => {
     if (props.multiple) {
       const value = ensureArray(props.modelValue ?? []).slice()
       const optionIndex = getValueIndex(value, option)
@@ -573,7 +578,7 @@ export const useSelect = (props: ISelectProps, emit) => {
     })
   }
 
-  const getValueIndex = (arr: any[] = [], option) => {
+  const getValueIndex = (arr: OptionValue[], option: OptionPublicInstance) => {
     if (isUndefined(option)) return -1
     if (!isObject(option.value)) return arr.indexOf(option.value)
 
@@ -582,7 +587,12 @@ export const useSelect = (props: ISelectProps, emit) => {
     })
   }
 
-  const scrollToOption = (option) => {
+  const scrollToOption = (
+    option:
+      | OptionPublicInstance
+      | OptionPublicInstance[]
+      | SelectStates['selected']
+  ) => {
     const targetOption = isArray(option) ? option[0] : option
     let target = null
 
@@ -606,12 +616,12 @@ export const useSelect = (props: ISelectProps, emit) => {
     scrollbarRef.value?.handleScroll()
   }
 
-  const onOptionCreate = (vm: SelectOptionProxy) => {
+  const onOptionCreate = (vm: OptionPublicInstance) => {
     states.options.set(vm.value, vm)
     states.cachedOptions.set(vm.value, vm)
   }
 
-  const onOptionDestroy = (key, vm: SelectOptionProxy) => {
+  const onOptionDestroy = (key: OptionValue, vm: OptionPublicInstance) => {
     if (states.options.get(key) === vm) {
       states.options.delete(key)
     }
@@ -689,7 +699,9 @@ export const useSelect = (props: ISelectProps, emit) => {
     }
   }
 
-  const getValueKey = (item) => {
+  const getValueKey = (
+    item: OptionPublicInstance | SelectStates['selected'][0]
+  ) => {
     return isObject(item.value) ? get(item.value, props.valueKey) : item.value
   }
 
@@ -717,7 +729,7 @@ export const useSelect = (props: ISelectProps, emit) => {
       : []
   })
 
-  const navigateOptions = (direction) => {
+  const navigateOptions = (direction: 'prev' | 'next') => {
     if (!expanded.value) {
       expanded.value = true
       return
diff --git a/packages/components/tree-select/src/cache-options.ts b/packages/components/tree-select/src/cache-options.ts
index b23afd2f39..0f84c53925 100644
--- a/packages/components/tree-select/src/cache-options.ts
+++ b/packages/components/tree-select/src/cache-options.ts
@@ -27,6 +27,9 @@ export default defineComponent({
       () => {
         props.data.forEach((item) => {
           if (!select.states.cachedOptions.has(item.value)) {
+            // TODO: the type of 'item' is not compatible with the type of 'cachedOptions',
+            // which may indicate potential runtime issues.
+            // @ts-expect-error
             select.states.cachedOptions.set(item.value, item)
           }
         })