Mrs.Oby, you can apply for Tourist Visa for family visit, the requirements are:
1.One completed visa application form with a recently taken passport photo stuck on it; all the items on the application form should be completed neatly with genuine information; false or incomplete information and illegible characters may lead to refusal of a visa.

2. Your passport and photocopy data pages and all the Chinese visas on your passport (if available)

3. invitation letter from your husband, the copy of his passport data pages, residence permit, Chinese visa.

I am not sure you can get a visa with an invitation from your husband in China. And I am not sure you can apply for a tourist visa to visit your husband as Nigerians are allowed only if they are here to buy things. Or study.