how to find who is use my family share?

Hi weizhao1, in order to find out who is in your family share, follow these steps in order:

1. Go into the Settings app

2. Press on your name at the top (which should pull up your Apple ID page)

3. Press on Family Sharing

There, you should see your family share. You can see who is in your iCloud Family on that page. If you don't recognize a member, press on their name and press on "Remove from Family" which is in red. It is highly advisable to change your password in that situation.