diff --git a/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README.md b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README.md
index fa02a2e88007a..0ce6daf0e323b 100644
--- a/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README.md	
+++ b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README.md	
@@ -286,4 +286,39 @@ function minAddToMakeValid(s: string): number {
 
 <!-- solution:end -->
 
+<!-- solution:start -->
+
+### 方法三：替换 + 递归
+
+<!-- tabs:start -->
+
+#### TypeScript
+
+```ts
+function minAddToMakeValid(s: string): number {
+    const l = s.length;
+    s = s.replace('()', '');
+
+    return s.length === l ? l : minAddToMakeValid(s);
+}
+```
+
+#### JavaScript
+
+```js
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var minAddToMakeValid = function (s) {
+    const l = s.length;
+    s = s.replace('()', '');
+    return s.length === l ? l : minAddToMakeValid(s);
+};
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
 <!-- problem:end -->
diff --git a/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README_EN.md b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README_EN.md
index ed2031eba82c5..4710133bd20ad 100644
--- a/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README_EN.md	
+++ b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/README_EN.md	
@@ -284,4 +284,39 @@ function minAddToMakeValid(s: string): number {
 
 <!-- solution:end -->
 
+<!-- solution:start -->
+
+### Solution 3: Replace + recursion
+
+<!-- tabs:start -->
+
+#### TypeScript
+
+```ts
+function minAddToMakeValid(s: string): number {
+    const l = s.length;
+    s = s.replace('()', '');
+
+    return s.length === l ? l : minAddToMakeValid(s);
+}
+```
+
+#### JavaScript
+
+```js
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var minAddToMakeValid = function (s) {
+    const l = s.length;
+    s = s.replace('()', '');
+    return s.length === l ? l : minAddToMakeValid(s);
+};
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
 <!-- problem:end -->
diff --git a/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/Solution3.js b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/Solution3.js
new file mode 100644
index 0000000000000..c9403ec3de6e9
--- /dev/null
+++ b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/Solution3.js	
@@ -0,0 +1,9 @@
+/**
+ * @param {string} s
+ * @return {number}
+ */
+var minAddToMakeValid = function (s) {
+    const l = s.length;
+    s = s.replace('()', '');
+    return s.length === l ? l : minAddToMakeValid(s);
+};
diff --git a/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/Solution3.ts b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/Solution3.ts
new file mode 100644
index 0000000000000..82e35b7c75937
--- /dev/null
+++ b/solution/0900-0999/0921.Minimum Add to Make Parentheses Valid/Solution3.ts	
@@ -0,0 +1,6 @@
+function minAddToMakeValid(s: string): number {
+    const l = s.length;
+    s = s.replace('()', '');
+
+    return s.length === l ? l : minAddToMakeValid(s);
+}