Can American students apply for green card status and return to China?

I have a green card. Before the green card was issued, I traveled to and from China. As long as my first visa to the United States has not expired, I can travel back and forth without any problems. . Green cards can't be mailed home for at least six months. . I waited for more than a year to receive it. . . In short, as long as it is within the visa period, there is no problem. . make no difference