I plan to immigrate to the United States, but I have some things to deal with in China. Can I postpone going to America for a while? Is this delay still valid?

You must report in the United States within the validity period of your visa. When you enter the customs, you will be asked to provide an American address or you have filled it in when you apply, and your green card will naturally be mailed to that address.

When you enter the customs, your passport will be stamped. This is your temporary green card. With this chapter, you can freely enter and leave the United States within the validity period (half a year).

After you report it, you can fly back to China the next day (but don't talk to the border guards when you go in to avoid trouble). After you return to China, you should deal with your own affairs quickly and go to America within six months.

Never put it off, it's useless.