diff --git a/ios/sdk/WeexSDK/Sources/Bridge/WXJSCoreBridge.mm b/ios/sdk/WeexSDK/Sources/Bridge/WXJSCoreBridge.mm
index 9293fa54c3..9caff56495 100644
--- a/ios/sdk/WeexSDK/Sources/Bridge/WXJSCoreBridge.mm
+++ b/ios/sdk/WeexSDK/Sources/Bridge/WXJSCoreBridge.mm
@@ -80,6 +80,7 @@ - (void)dealloc
 {
     _jsContext.instanceId = nil;
     __block JSContext* theContext = _jsContext;
+    _jsContext = nil; // Make sure that the context MUST be freed in JS thread.
     WXPerformBlockOnBridgeThreadForInstance(^{
          theContext = nil; // release the context in js thread to avoid main-thread deadlock
     }, _weexInstanceId);
diff --git a/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m b/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
index 360ad4f9bd..7a22748e87 100644
--- a/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
+++ b/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
@@ -606,6 +606,10 @@ - (BOOL)_handleConfigCenter
         BOOL alwaysUseMRCForObjectToWeexCore = [[configCenter configForKey:@"iOS_weex_ext_config.alwaysUseMRC" defaultValue:@(NO) isDefault:NULL] boolValue];
         ConvertSwitches(isIOS13, useMRCForInvalidJSONObject, alwaysUseMRCForObjectToWeexCore);
     }
+    else {
+        BOOL isIOS13 = [[[UIDevice currentDevice] systemVersion] integerValue] == 13;
+        ConvertSwitches(isIOS13, YES, NO);
+    }
     return NO;
 }