diff --git a/src/common/Extend.ts b/src/common/Extend.ts
index b385726..585c47e 100644
--- a/src/common/Extend.ts
+++ b/src/common/Extend.ts
@@ -861,3 +861,25 @@ Object.defineProperties(Array.prototype, {
     }
 
 });
+
+interface Map<K, V> {
+    /**
+     * 只针对V为number的Map, 有值的话, 加上V, 没值则直接set
+     * V为其他类型时, 直接set
+     * @param key
+     * @param value
+     */
+    inc?(key: K, value: V): this;
+}
+
+Object.defineProperties(Map.prototype, {
+    inc: {
+        value: function<K, V> (key: K, value: V) {
+            if (typeof value == 'number') {
+                this.set(key, (this.get(key) || 0) + value );
+            } else {
+                this.set(key, value);
+            }
+        }
+    }
+});