Why i need this? Apple itself has a service to download offline map and negivate, but this service is closed in China... What the hell??? Is there some other apps can do this for me? The WorkOutDoors is test, offline map is OK but not good for an offline negivation...

Apple Watch Ultra 上的离线地图测试 (testwo.com)

Better forget it... All solutions are not stable or have a good experice... Get a Garmin if you really need this funciton.