A polygamous family immigrated to China. According to the law of China, how to deal with polygamy?

In this case, the treatment method is as follows:

African polygamy is a fait accompli. According to the laws of China, this is allowed.

But he can't continue to get married.

For example, when New China was founded, many people were polygamous, which was incompatible with the laws of New China.

But they can't be separated, so they are allowed to keep polygamy, but they can't remarry.