Thanks a lot. problem solved.
There is no way to add a moderator ?
Categories > Options* > Access Control > [Search For User] > Priveliges > Tick Moderator > Save
Do this for each category and each moderator.
You can then create a group called Moderators, give them a badge like is on the left of my post(assuming you use Lavender). And just add the moderators into that group.
I want to know, after I add an user group into a categoriy, how can I remove it? I only looked an add button but not remove button.
@shouhuanxiaoji When you remove all the permissions the user should be removed from the category