Canadian immigrant children do not need immigration supervision.

It's no problem to change cards. According to the regulations of Immigration Canada, the time you spend with Canadian citizens living abroad is also regarded as your time in Canada. Did not specify whether it was an adult or a child. Your child is a Canadian citizen, and you live with him in China. If you meet this requirement, it should be no problem to change your card. When changing your card, the immigration officer may ask you why you left your child in China. You can give him a reasonable explanation.