Both husband and wife are citizens of China. In which jurisdiction are Canadian immigrants divorced?

Divorce is the best choice in China. The court of a party's domicile in China (usually the domicile of China) has jurisdiction.

It should be noted that if one party conducts divorce proceedings in Canada, even if it obtains a divorce decree from a Canadian court, it must apply for recognition in a domestic court in China. Moreover, even if the decree is recognized by the China court, it only recognizes a part of the dissolution of the relationship between husband and wife. The China court does not recognize the contents of the Canadian (or other overseas) laws on property distribution and child custody, and both parties still need to file another lawsuit in the domestic court of China. Therefore, if the husband and wife's property is located in China, or the children still belong to China citizens, it will be difficult to avoid litigation in China.