Why is my address book synchronized with other mobile phones? How to solve it?

Why is your phone address book synchronized with other phones? This must be that you logged in your ID password on someone else's mobile phone. You didn't quit when you logged in. So your address book is synchronized with other people's mobile phones. You need to find this mobile phone, cancel the previous ID password and exit. So your address book won't be synchronized with other people's mobile phones. If you don't quit, keep updating the address book, and it will also be displayed on your mobile phone. In other words, you can have someone else's address book, and so can others.