Can I go to Hongkong with a Canadian passport and then go back to the mainland with a China passport?

You enter Hong Kong with a Canadian passport, so what kind of travel documents do you use when you leave Hong Kong airport, check in and go through exit management procedures? If you still use a Canadian passport, you will have no problem leaving Hong Kong. However, when you arrive in the Mainland, if you give your China passport to the border police when you enter the customs, there will be a problem: your travel document does not match the passenger information in the computer, because you used a Canadian passport when you left Hong Kong and checked in. You know, when you go through the immigration formalities, your information has already been transmitted to the computer of the border inspector, and he will stamp it before releasing it.

If you enter Hong Kong with a Canadian passport and leave Hong Kong with a China passport, it is even more impossible, because there is no entry record of Hong Kong in your China passport. The police will investigate how you got into Hong Kong. We should know that the entry and exit management of any country in the world has the same principle: which country's passport can only be used for entry and exit, even if dual nationality is recognized.