diff --git a/problems/0701.二叉搜索树中的插入操作.md b/problems/0701.二叉搜索树中的插入操作.md
index 06e1c88f..599dd073 100644
--- a/problems/0701.二叉搜索树中的插入操作.md
+++ b/problems/0701.二叉搜索树中的插入操作.md
@@ -337,16 +337,15 @@ class Solution:
     def insertIntoBST(self, root: TreeNode, val: int) -> TreeNode:
         if not root: 
             return TreeNode(val)
-        parent = None
+        parent = None # 此步可以省略
         cur = root
 
         # 用while循环不断地找新节点的parent
         while cur: 
+            parent = cur  # 首先保存当前非空节点作为下一次迭代的父节点
             if cur.val < val: 
-                parent = cur
                 cur = cur.right
             elif cur.val > val: 
-                parent = cur
                 cur = cur.left
 
         # 运行到这意味着已经跳出上面的while循环,