diff --git a/library/think/Cache.php b/library/think/Cache.php
index dcf3dd05..df2ebcb0 100644
--- a/library/think/Cache.php
+++ b/library/think/Cache.php
@@ -69,16 +69,35 @@ class Cache
     }
 
     /**
-     * 读取缓存
+     * 判断缓存是否存在
      * @access public
-     * @param string $name 缓存标识
-     * @return mixed
+     * @param string $name 缓存变量名
+     * @return bool
      */
-    public static function get($name)
+    public static function has($name)
     {
         self::init();
         self::$readTimes++;
-        return self::$handler->get($name);
+        return self::$handler->has($name);
+    }
+
+    /**
+     * 读取缓存
+     * @access public
+     * @param string $name 缓存标识
+     * @param string $default 默认值
+     * @return mixed
+     */
+    public static function get($name, $default = null)
+    {
+        self::init();
+        self::$readTimes++;
+        $result = self::$handler->get($name);
+        if (false !== $result) {
+            return $result;
+        } else {
+            return $default;
+        }
     }
 
     /**
diff --git a/library/think/cache/driver/File.php b/library/think/cache/driver/File.php
index 29cd3773..7d4c56e7 100644
--- a/library/think/cache/driver/File.php
+++ b/library/think/cache/driver/File.php
@@ -11,8 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
-
 /**
  * 文件类型缓存类
  * @author    liu21st <liu21st@gmail.com>
@@ -86,6 +84,18 @@ class File
         return $this->options['path'] . $filename;
     }
 
+    /**
+     * 判断缓存是否存在
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        $filename = $this->filename($name);
+        return is_file($filename);
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/library/think/cache/driver/Lite.php b/library/think/cache/driver/Lite.php
index 0a3a838b..d5729dc6 100644
--- a/library/think/cache/driver/Lite.php
+++ b/library/think/cache/driver/Lite.php
@@ -11,8 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
-
 /**
  * 文件类型缓存类
  * @author    liu21st <liu21st@gmail.com>
@@ -53,6 +51,18 @@ class Lite
         return $this->options['path'] . $this->options['prefix'] . md5($name) . '.php';
     }
 
+    /**
+     * 判断缓存是否存在
+     * @access public
+     * @param string $name 缓存变量名
+     * @return mixed
+     */
+    public function has($name)
+    {
+        $filename = $this->filename($name);
+        return is_file($filename);
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/library/think/cache/driver/Memcache.php b/library/think/cache/driver/Memcache.php
index 8ca55f07..93b63de2 100644
--- a/library/think/cache/driver/Memcache.php
+++ b/library/think/cache/driver/Memcache.php
@@ -11,7 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
 use think\Exception;
 
 class Memcache
@@ -56,6 +55,18 @@ class Memcache
         }
     }
 
+    /**
+     * 判断缓存
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        $name = $this->options['prefix'] . $name;
+        return $this->handler->get($name) ? true : false;
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/library/think/cache/driver/Memcached.php b/library/think/cache/driver/Memcached.php
index 50082a1e..32063246 100644
--- a/library/think/cache/driver/Memcached.php
+++ b/library/think/cache/driver/Memcached.php
@@ -11,8 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
-
 class Memcached
 {
     protected $handler;
@@ -62,6 +60,18 @@ class Memcached
         }
     }
 
+    /**
+     * 判断缓存
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        $name = $this->options['prefix'] . $name;
+        return $this->handler->get($name) ? true : false;
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/library/think/cache/driver/Redis.php b/library/think/cache/driver/Redis.php
index 25febbf0..ec2d3e93 100644
--- a/library/think/cache/driver/Redis.php
+++ b/library/think/cache/driver/Redis.php
@@ -11,9 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
-use think\Exception;
-
 /**
  * Redis缓存驱动，适合单机部署、有前端代理实现高可用的场景，性能最好
  * 有需要在业务层实现读写分离、或者使用RedisCluster的需求，请使用Redisd驱动
@@ -56,6 +53,17 @@ class Redis
         }
     }
 
+    /**
+     * 判断缓存
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        return $this->handler->get($this->options['prefix'] . $name) ? true : false;
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/library/think/cache/driver/Redisd.php b/library/think/cache/driver/Redisd.php
index e3bc80e7..94645dd5 100644
--- a/library/think/cache/driver/Redisd.php
+++ b/library/think/cache/driver/Redisd.php
@@ -12,7 +12,6 @@
 namespace think\cache\driver;
 
 use think\App;
-use think\Cache;
 use think\Exception;
 use think\Log;
 
@@ -199,6 +198,17 @@ class Redisd
         return $this;
     }
 
+    /**
+     * 判断缓存
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        return $this->get($name) ? true : false;
+    }
+
     /**
      * 读取缓存
      *
diff --git a/library/think/cache/driver/Sqlite.php b/library/think/cache/driver/Sqlite.php
index e4689d61..e5e47fe7 100644
--- a/library/think/cache/driver/Sqlite.php
+++ b/library/think/cache/driver/Sqlite.php
@@ -11,7 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
 use think\Exception;
 
 /**
@@ -47,6 +46,20 @@ class Sqlite
         $this->handler = $func($this->options['db']);
     }
 
+    /**
+     * 判断缓存
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        $name   = $this->options['prefix'] . sqlite_escape_string($name);
+        $sql    = 'SELECT value FROM ' . $this->options['table'] . ' WHERE var=\'' . $name . '\' AND (expire=0 OR expire >' . $_SERVER['REQUEST_TIME'] . ') LIMIT 1';
+        $result = sqlite_query($this->handler, $sql);
+        return sqlite_num_rows($result);
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/library/think/cache/driver/Wincache.php b/library/think/cache/driver/Wincache.php
index bc1b35de..937fa344 100644
--- a/library/think/cache/driver/Wincache.php
+++ b/library/think/cache/driver/Wincache.php
@@ -11,7 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
 use think\Exception;
 
 /**
@@ -41,6 +40,18 @@ class Wincache
         }
     }
 
+    /**
+     * 判断缓存
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        $name = $this->options['prefix'] . $name;
+        return wincache_ucache_exists($name);
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/library/think/cache/driver/Xcache.php b/library/think/cache/driver/Xcache.php
index bb6f277e..10b0740d 100644
--- a/library/think/cache/driver/Xcache.php
+++ b/library/think/cache/driver/Xcache.php
@@ -11,7 +11,6 @@
 
 namespace think\cache\driver;
 
-use think\Cache;
 use think\Exception;
 
 /**
@@ -41,6 +40,18 @@ class Xcache
         }
     }
 
+    /**
+     * 判断缓存
+     * @access public
+     * @param string $name 缓存变量名
+     * @return bool
+     */
+    public function has($name)
+    {
+        $name = $this->options['prefix'] . $name;
+        return xcache_isset($name);
+    }
+
     /**
      * 读取缓存
      * @access public
diff --git a/tests/thinkphp/library/think/cache/driver/cacheTestCase.php b/tests/thinkphp/library/think/cache/driver/cacheTestCase.php
index c7bd407c..5097461b 100644
--- a/tests/thinkphp/library/think/cache/driver/cacheTestCase.php
+++ b/tests/thinkphp/library/think/cache/driver/cacheTestCase.php
@@ -75,7 +75,7 @@ abstract class cacheTestCase extends \PHPUnit_Framework_TestCase
         $array = $cache->get('array_test');
         $this->assertArrayHasKey('array_test', $array);
         $this->assertEquals('array_test', $array['array_test']);
-        
+
         $result = $cache->set('no_expire', 1, 0);
         $this->assertTrue($result);
     }
@@ -88,9 +88,9 @@ abstract class cacheTestCase extends \PHPUnit_Framework_TestCase
     public function testExists()
     {
         $cache = $this->prepare();
-        $this->assertNotEmpty($cache->get('string_test'));
-        $this->assertNotEmpty($cache->get('number_test'));
-        $this->assertFalse($cache->get('not_exists'));
+        $this->assertNotEmpty($cache->has('string_test'));
+        $this->assertNotEmpty($cache->has('number_test'));
+        $this->assertFalse($cache->has('not_exists'));
     }
 
     /**
@@ -101,7 +101,7 @@ abstract class cacheTestCase extends \PHPUnit_Framework_TestCase
     public function testGetNonExistent()
     {
         $cache = $this->getCacheInstance();
-        $this->assertFalse($cache->get('non_existent_key'));
+        $this->assertFalse($cache->get('non_existent_key', false));
     }
 
     /**