diff --git a/problems/0110.平衡二叉树.md b/problems/0110.平衡二叉树.md
index 9d43407a..313aeff2 100644
--- a/problems/0110.平衡二叉树.md
+++ b/problems/0110.平衡二叉树.md
@@ -614,8 +614,10 @@ var isBalanced = function(root) {
         if(node === null) return 0;
         // 3. 确定单层递归逻辑
         let leftDepth = getDepth(node.left); //左子树高度
-        let rightDepth = getDepth(node.right); //右子树高度
+        // 当判定左子树不为平衡二叉树时,即可直接返回-1
         if(leftDepth === -1) return -1;
+        let rightDepth = getDepth(node.right); //右子树高度
+        // 当判定右子树不为平衡二叉树时,即可直接返回-1
         if(rightDepth === -1) return -1;
         if(Math.abs(leftDepth - rightDepth) > 1) {
             return -1;