Nomrally after your child's immigration visa was denial, the US Consulate in Guangzhou will return the whole case to the National Visa Center (NVC) with the suggetion of revocation of the I-130, then NVC will return it to USCIS for reconsideration. If USCIS think the US Consulate's reason of revocation suggestion is not justified, USCIS will forward the case to NVC, then to the US Consulate again for consideration and interviewing your child for approval. USCIS will send you a letter to tell you their decision. You do not need to do anything in this case.
But if USCIS think the US Consulate's suggestion is correct, then USCIS will revoke your I-130 and they will send a revoction notice to you. Then, you have to file a new I-130 again.
So, you may just wait for the USCIS notice and do nothing by this time. You may contact NVC and contact USCIS to see where your case is location and what the status is by this time if you want.
