diff --git a/packages/components/input/src/input.ts b/packages/components/input/src/input.ts
index 55db62ea46..5b291a07b8 100644
--- a/packages/components/input/src/input.ts
+++ b/packages/components/input/src/input.ts
@@ -96,7 +96,9 @@ export const inputEmits = {
   clear: () => true,
   mouseleave: (evt: MouseEvent) => evt instanceof MouseEvent,
   mouseenter: (evt: MouseEvent) => evt instanceof MouseEvent,
-  keydown: (evt: KeyboardEvent) => evt instanceof KeyboardEvent,
+  // NOTE: when autofill by browser, the keydown event is instanceof Event, not KeyboardEvent
+  // relative bug report https://github.com/element-plus/element-plus/issues/6665
+  keydown: (evt: KeyboardEvent | Event) => evt instanceof Event,
   compositionstart: (evt: CompositionEvent) => evt instanceof CompositionEvent,
   compositionupdate: (evt: CompositionEvent) => evt instanceof CompositionEvent,
   compositionend: (evt: CompositionEvent) => evt instanceof CompositionEvent,