diff --git a/app/data/controller/base/Discount.php b/app/data/controller/base/Discount.php
index 7878cecbf..6ce742207 100644
--- a/app/data/controller/base/Discount.php
+++ b/app/data/controller/base/Discount.php
@@ -64,9 +64,9 @@ class Discount extends Controller
             }
             $vo['items'] = json_encode($rule, JSON_UNESCAPED_UNICODE);
         } else {
-            $this->levels = UserUpgradeService::instance()->levels();
+            $this->levels = UserUpgradeService::levels();
             if (empty($this->levels)) $this->error('未配置用户等级！');
-            if (!empty($vo['items'])) foreach (json_decode($vo['items'], true) as $item) {
+            foreach ($vo['items'] ?? [] as $item) {
                 $vo["_level_{$item['level']}"] = $item['discount'];
             }
         }
diff --git a/app/data/service/UserUpgradeService.php b/app/data/service/UserUpgradeService.php
index ad322613f..d9c829f6b 100644
--- a/app/data/service/UserUpgradeService.php
+++ b/app/data/service/UserUpgradeService.php
@@ -21,7 +21,7 @@ class UserUpgradeService extends Service
      * 获取用户等级数据
      * @return array
      */
-    public function levels(): array
+    public static function levels(): array
     {
         $model = BaseUserUpgrade::mk()->where(['status' => 1]);
         return $model->order('number asc')->column('*', 'number');