diff --git a/application/admin/controller/general/Attachment.php b/application/admin/controller/general/Attachment.php
index 80414dfcf9a361a26c56d027cce08f9905efc118..d70ffbc591db46ca9fb9ed19c3ebd64766abe7cc 100644
--- a/application/admin/controller/general/Attachment.php
+++ b/application/admin/controller/general/Attachment.php
@@ -36,9 +36,11 @@ class Attachment extends Backend
             $filter = $this->request->request('filter');
             $filterArr = (array)json_decode($filter, TRUE);
             if (isset($filterArr['mimetype']) && stripos($filterArr['mimetype'], ',') !== false) {
-                $this->request->get(['filter' => json_encode(array_merge($filterArr, ['mimetype' => '']))]);
-                $mimetypeQuery = function ($query) use ($filterArr) {
-                    $mimetypeArr = explode(',', $filterArr['mimetype']);
+				$mimetype=$filterArr['mimetype'];
+				unset($filterArr['mimetype']);
+                $this->request->get(['filter' => json_encode($filterArr)]);
+                $mimetypeQuery = function ($query) use ($mimetype) {
+                    $mimetypeArr = explode(',', $mimetype);
                     foreach ($mimetypeArr as $index => $item) {
                         $query->whereOr('mimetype', 'like', '%' . $item . '%');
                     }