diff --git a/helper.php b/helper.php
index 7543fcce..bedb39f8 100644
--- a/helper.php
+++ b/helper.php
@@ -200,7 +200,7 @@ function U($url = '', $vars = '', $suffix = true, $domain = false)
     return \think\Url::build($url, $vars, $suffix, $domain);
 }
 
-function session($name, $value = '')
+function session($name, $value = '', $prefix = null)
 {
     if (is_array($name)) {
         // 初始化
@@ -209,14 +209,14 @@ function session($name, $value = '')
         // 清除
         \think\Session::clear($value);
     } elseif ('' === $value) {
-        // 获取
-        return \think\Session::get($name);
+        // 判断或获取
+        return 0 === strpos($name, '?') ? \think\Session::has(substr($name, 1), $prefix) : \think\Session::get($name, $prefix);
     } elseif (is_null($value)) {
         // 删除session
-        return \think\Session::delete($name);
+        return \think\Session::delete($name, $prefix);
     } else {
         // 设置session
-        return \think\Session::set($name, $value);
+        return \think\Session::set($name, $value, $prefix);
     }
 }
 
diff --git a/library/think/Response.php b/library/think/Response.php
index 4f985948..cdb32bce 100644
--- a/library/think/Response.php
+++ b/library/think/Response.php
@@ -174,7 +174,7 @@ class Response
             'code' => $code,
             'msg'  => $msg,
             'data' => $data,
-            'url'  => is_null($url) ? $_SERVER["HTTP_REFERER"] : $url,
+            'url'  => is_null($url) && isset($_SERVER["HTTP_REFERER"]) ? $_SERVER["HTTP_REFERER"] : $url,
             'wait' => $wait,
         ];