You have nothing much to worry about..if i was you i would deny ever getting married...end of story!!!!!!The first question she will be asked is why didnt she say before you got your citizenship?what is her motive/reason to come forward now? The chances that United States will go to china to spend money to investigate an issue that they dont even know if its true and not a serious crime are very slim....besides that, you are not the only one being accused of lying...how many people do you think have come forward with similar allegations???
It is not that easy. If USCIS investigate and ask the OP to speak truth again under oath, if he again say No such previous marriage, then there is absolutely no chance if USCIS did find out he was married before.
Counter blackmalinging the wife may work or may nor work. It may not work if the wife get bored of living here and decide
to go back to China anyway (such things are quite common nowadays).
By the way, in China (as well of many Eastern European countries) there was a time, almost 100% of people were once young vanguards, 90% were/are youth leagure and yiqte a lot were/are COmmunist party party memeber. If husband and wife know this, shoudl they blackmail each other on that part too? Does USCIS give a damn?