diff --git a/docs/chapter_hashing/hash_map.md b/docs/chapter_hashing/hash_map.md
index 2e2e57263..d8244d80a 100644
--- a/docs/chapter_hashing/hash_map.md
+++ b/docs/chapter_hashing/hash_map.md
@@ -646,7 +646,7 @@ $$
         /* 添加操作 */
         public set(key: number, val: string) {
             let index = this.hashFunc(key);
-            this.bucket[index] = new Entry(index, val);
+            this.bucket[index] = new Entry(key, val);
         }
     
         /* 删除操作 */