diff --git a/Storage/Storage/Internal/Storage/StorageController.cs b/Storage/Storage/Internal/Storage/StorageController.cs
index 3a79c50..551d0ab 100644
--- a/Storage/Storage/Internal/Storage/StorageController.cs
+++ b/Storage/Storage/Internal/Storage/StorageController.cs
@@ -50,13 +50,15 @@ namespace LeanCloud.Storage.Internal.Storage {
             return null;
         }
 
-        public void Delete(string filename) {
+        public Task Delete(string filename) {
             if (storage == null) {
-                return;
+                return Task.CompletedTask;
             }
 
             string path = GetFileFullPath(filename);
-            IOFile.Delete(path);
+            return Task.Run(() => {
+                IOFile.Delete(path);
+            });
         }
 
         private string GetFileFullPath(string filename) {
diff --git a/Storage/Storage/LCUser.cs b/Storage/Storage/LCUser.cs
index abca204..0f4e29a 100644
--- a/Storage/Storage/LCUser.cs
+++ b/Storage/Storage/LCUser.cs
@@ -89,7 +89,7 @@ namespace LeanCloud.Storage {
                     currentUser = ParseObject(data) as LCUser;
                 } catch (Exception e) {
                     LCLogger.Error(e);
-                    LCInternalApplication.StorageController.Delete(USER_DATA);
+                    await LCInternalApplication.StorageController.Delete(USER_DATA);
                 }
             }
             return currentUser;
@@ -513,8 +513,7 @@ namespace LeanCloud.Storage {
         public static Task Logout() {
             currentUser = null;
             // 清理持久化数据
-            LCInternalApplication.StorageController.Delete(USER_DATA);
-            return Task.FromResult<object>(null);
+            return LCInternalApplication.StorageController.Delete(USER_DATA);
         }
 
         /// <summary>