Can I report his illegal immigration when I apply for political asylum in the United States?

You can report it, just go to the American embassy and give them a letter (ok in Chinese), and the consequence is that he will definitely not be able to do it, three months? Even after three or even thirty years, he may not have a chance to cheat the US government into blacklisting.

He went to the relevant government agencies in China (Foreign Affairs Office, former unit, Public Security Bureau) to report him, and he was finished. He actually slandered his country to gain foreign status.

Every year, the United States exerts human rights pressure on the China government through political asylum in these cases, which is the worst.

So weigh it yourself, (it's not a vendetta, it's unnecessary, there's something to communicate). You do this, he's not human on either side, and he's finished. . . . . . . . .

Again, even if he gets an American green card and you report it, he still needs to go to court to explain your report, and there is still a great possibility that he will lose his green card.