diff --git a/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m b/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
index ee72b35721..afe079bec8 100644
--- a/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
+++ b/ios/sdk/WeexSDK/Sources/Model/WXSDKInstance.m
@@ -769,8 +769,12 @@ - (NSURL *)completeURL:(NSString *)url
     if (!url) {
         return nil;
     }
-    
-    return [NSURL URLWithString:url relativeToURL:_scriptURL];
+    NSURL *result = [NSURL URLWithString:url relativeToURL:_scriptURL];
+    if (result) {
+        return result;
+    }
+    // if result is nil, try url-encode the 'url' string.
+    return [NSURL URLWithString:[url stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding] relativeToURL:_scriptURL];
 }
 
 - (BOOL)checkModuleEventRegistered:(NSString*)event moduleClassName:(NSString*)moduleClassName