I have not received my U.S. green card. How to calculate the validity period of my immigrant visa? Can I enter the United States again?

First of all, if you have not received your green card, you need to go to the local US Immigration Bureau to apply for a stamp (blue, with validity period) on your Chinese passport to prove your legal status in the United States. Then, you can return to your home country again. But you must return to the United States within the validity period stamped by the immigration office on your passport. When entering the country, you can prove your legal status by showing the immigration stamp on your passport.