Yes! Pushy supports notification delivery to Android & iOS devices worldwide including mainland China, and thousands of companies are already using Pushy to deliver notifications reliably in this region.
We make use of a proprietary notification gateway built with MQTT to deliver notifications to Android devices worldwide. Therefore, we aren't impacted by the fact Firebase Cloud Messaging is blocked in China. Furthermore, our solution does not depend on Google Play Services, which most Android phones in China lack.
Note: Web Push on Android is currently not available in mainland China as the technology makes use of FCM behind-the-scenes, which is blocked in China. Consider bundling your website or web app inside an app using a hybrid app development platform such as Cordova or React Native.