My girlfriend immigrated to Canada and has not yet obtained nationality. Then how can we get married? Can she return to China for a long time? We want to live in China. (detailed answer

You can get married in China or Canada. There is no limit. If you want to live in China, why immigrate to Canada? If she wants to live in China for a long time, she will not be restricted by immigration supervision if she wants to be naturalized in Canada, but it will have certain influence in China. If she doesn't naturalize in Canada, it will have the influence of immigration supervision. This is not a satisfactory solution. You can reunite with her after marriage and then live with her in Canada.