diff --git a/problems/0530.二叉搜索树的最小绝对差.md b/problems/0530.二叉搜索树的最小绝对差.md
index 143bd053..03c48d9c 100644
--- a/problems/0530.二叉搜索树的最小绝对差.md
+++ b/problems/0530.二叉搜索树的最小绝对差.md
@@ -151,7 +151,30 @@ public:
 
 
 Java：
-
+递归
+```java
+class Solution {
+    TreeNode pre;// 记录上一个遍历的结点
+    int result = Integer.MAX_VALUE;
+    public int getMinimumDifference(TreeNode root) {
+       if(root==null)return 0;
+       traversal(root);
+       return result;
+    }
+    public void traversal(TreeNode root){
+        if(root==null)return;
+        //左
+        traversal(root.left);
+        //中
+        if(pre!=null){
+            result = Math.min(result,root.val-pre.val);
+        }
+        pre = root;
+        //右
+        traversal(root.right);
+    }
+}
+```
 ```Java
 class Solution {
     TreeNode pre;// 记录上一个遍历的结点