diff --git a/docs/chapter_tree/binary_tree.md b/docs/chapter_tree/binary_tree.md
index cf6cad4..5913a1a 100644
--- a/docs/chapter_tree/binary_tree.md
+++ b/docs/chapter_tree/binary_tree.md
@@ -68,8 +68,7 @@ comments: true
         this.val = (val === undefined ? 0 : val) // 结点值
         this.left = (left === undefined ? null : left) // 左子结点指针
         this.right = (right === undefined ? null : right) // 右子结点指针
-  }
-
+    }
     ```
 
 === "TypeScript"