diff --git a/extend/catcher/library/rate/Redis.php b/extend/catcher/library/rate/Redis.php
index 09268b1..be6fd62 100644
--- a/extend/catcher/library/rate/Redis.php
+++ b/extend/catcher/library/rate/Redis.php
@@ -14,9 +14,18 @@ use think\facade\Cache;
 
 trait Redis
 {
+    /**
+     * @var \Redis
+     */
     protected $redis = null;
 
-    protected function getRedis()
+    /**
+     * 返回 redis
+     *
+     * @time 2020年07月02日
+     * @return \Redis
+     */
+    protected function getRedis(): \Redis
     {
         if (!$this->redis) {
             $this->redis = Cache::store('redis')->handler();
diff --git a/extend/catcher/library/rate/SlidingWindowLimit.php b/extend/catcher/library/rate/SlidingWindowLimit.php
index ef90e0a..071fb9e 100644
--- a/extend/catcher/library/rate/SlidingWindowLimit.php
+++ b/extend/catcher/library/rate/SlidingWindowLimit.php
@@ -8,3 +8,64 @@
 // +----------------------------------------------------------------------
 // | Author: JaguarJack [ njphper@gmail.com ]
 // +----------------------------------------------------------------------
+namespace catcher\library\rate;
+
+use catcher\exceptions\FailedException;
+
+/**
+ * 滑动窗口
+ *
+ * Class SlidingWindowLimit
+ * @package catcher\library\rate
+ */
+class SlidingWindowLimit
+{
+    use Redis;
+
+    protected $key;
+
+    protected $limit = 10;
+
+    /**
+     * @var int
+     */
+    protected $window = 5;
+
+    public function __construct($key)
+    {
+        $this->key = $key;
+    }
+
+
+    public function overflow()
+    {
+        $now = microtime(true) * 1000;
+
+        $redis = $this->getRedis();
+        // 开启管道
+        $redis->pipeline();
+        // 去除非窗口内的元素
+        $redis->zremrangeByScore($this->key, 0, $now - $this->window*1000);
+        // 获取集合内的所有元素数目
+        $redis->zcard($this->key);
+        // 增加元素
+        $redis->zadd($this->key, $now, $now);
+        // 设置过期
+        $redis->expire($this->key, $this->window);
+        // 执行管道内命令
+        $res = $redis->exec();
+
+        if ($res[1] > $this->limit) {
+            throw new FailedException('访问限制');
+        }
+
+        return true;
+    }
+
+    public function setWindow($time)
+    {
+        $this->window = $time;
+
+        return $this;
+    }
+}
\ No newline at end of file