Take "Mobile WeChat Version 8.0.28" as an example. In the other party's WeChat, just turn on the blacklist switch.

1. Open the mobile phone WeChat address book.

2. Choose a friend you want to blacklist.

3. Enter this friend's WeChat and click on the three points in the upper right corner.

4. Swipe right to open the Add Blacklist button.

After this setting, the WeChat friend will be blacklisted.