The ex-husband and children went to Australia on 20 12, and the last relative emigrated. Now, for the sake of children, we want to remarry. How to handle it? What are the conditions?

Just get married normally! He can get married when he returns to China with the civil affairs department where your account is located. Because he went to Australia with your ex-husband in 20 12, and he is still a citizen of China, you can go through the remarriage formalities at the civil affairs department where your registered permanent residence is located.

I don't know what kind of visa he has Is he an immigrant? All these will affect your application for immigration after marriage. . .