diff --git a/notes/26. 树的子结构.md b/notes/26. 树的子结构.md
index 26e2229d..542e5772 100644
--- a/notes/26. 树的子结构.md	
+++ b/notes/26. 树的子结构.md	
@@ -6,7 +6,7 @@
 
 ## 题目描述
 
-<div align="center"> <img src="https://cs-notes-1256109796.cos.ap-guangzhou.myqcloud.com/84a5b15a-86c5-4d8e-9439-d9fd5a4699a1.jpg" width="450"/> </div><br>
+<div align="center"> <img src="pics/offer26-sub-structure.png" width="500px"/> </div><br>
 
 ## 解题思路
 
diff --git a/notes/pics/offer26-sub-structure.png b/notes/pics/offer26-sub-structure.png
new file mode 100644
index 00000000..ec586875
Binary files /dev/null and b/notes/pics/offer26-sub-structure.png differ