I want to ask my husband to help me apply for a domestic tourist visa and take my children to Canada. Can I apply for immigration locally? I forgot to mention that my husband is a Canadian citizen.

If you can get a visa, you can also apply for immigration in Canada, but it may take a long time to apply in China (because your people are already in Canada), which seems to be 1-2 years, but ordinary tourist visas can't stay that long. Maybe it's better to visit relatives and stay longer. Anyway, you have a way to stay in Canada and wait for your visa, but I'm surprised you haven't applied for immigration yet. Even if you are in China, it only takes half a year for your husband to apply in Canada. If it is slow, it will only take one year. Do you have to get a tourist visa to Canada?