diff --git a/problems/0617.合并二叉树.md b/problems/0617.合并二叉树.md
index acdcc0aa..6a843763 100644
--- a/problems/0617.合并二叉树.md
+++ b/problems/0617.合并二叉树.md
@@ -262,10 +262,10 @@ class Solution {
         if (root1 == null) return root2;
         if (root2 == null) return root1;
 
-        TreeNode newRoot = new TreeNode(root1.val + root2.val);
-        newRoot.left = mergeTrees(root1.left,root2.left);
-        newRoot.right = mergeTrees(root1.right,root2.right);
-        return newRoot;
+        root1.val += root2.val;
+        root1.left = mergeTrees(root1.left,root2.left);
+        root1.right = mergeTrees(root1.right,root2.right);
+        return root1;
     }
 }
 ```