If the child is underage, can the immigrant applicant give up the temporary green card, and will the child's green card be cancelled?

That's right. When you arrive in the United States, the main applicant gives up his green card and goes back to China.

Then the child can stay in the United States, and his green card will not be cancelled.

But he is still a minor. What will happen in the future?

Have you thought about it?

If it hasn't arrived yet, the main applicant has given up.

Children give up when they don't come to America.