Sister immigrated, and dad was alone?

If you immigrate, you only get a temporary visa or permanent residence status, and your nationality is still in China or a citizen of China, it doesn't count. Of course, if your sister has joined the nationality of the immigrant country, generally speaking, China passport will be cancelled and China nationality will be lost, so even if you are alone, there is another situation that if you join an international relationship that recognizes dual nationality and keep your China passport, you can't be alone!

Generally speaking, let's see if we have a China passport!