Thanks for your suggestion. I tested but it seems this idea not work.
- first I disabled mobile web service (Site administration > Mobile app > Mobile settings) to close the access of all users.
- Then enabled web service feature in Administration > Advanced features
- Add an external web service with all functions as like as mobile web service functions.
- and define "Users as clients with token" for that.
but no success.
So I need to find a way to change the setting of mobile web service is such a way that can select which users can use it.