wordpress的管理面板以这种方式被打破的原因是什么？

What is the reason that admin panel of wordpress has been broken in such a way?

I don't understand your question properly but I think the style has broken. One of your Plugin stylesheets might have broken the admin site layout. Deacitvate each plugin one by one and check which plugin causing this issue.

Deactivate recently install plugins and check. otherwise dDeacitvate each plugin one by one and check.

Download source code of wordpress from https://wordpress.org/download/, drop database and do installation again. It will work.