Can a person pay two copies of social security?

You can't. Social security is a national social security system, which aims to protect the basic needs of citizens. A person can only have one valid social security account, and cannot have more than two accounts at the same time. When a person pays social security in two different places or institutions at the same time, there will be the problem of repeated payment and repeated enjoyment of social security benefits, which is contrary to the national social security policy.