How many years does it take for a China woman to marry an American man to become an American citizen?

About 3 years, but not necessarily can join.

After marriage 1 can apply for immigration.

The application materials need to be very detailed, including the process of meeting and proposing marriage. Mainly face-to-face signing. It usually takes about 1 year from application to face-to-face interview.

After the visa is passed, you can get a temporary green card after entering the country and apply for a permanent green card one year later. The inspection is very strict, and all your questions are very personal.

During the period from applying for naturalization to obtaining approval, you must maintain continuous residence. You can apply for naturalization three months before you have lived continuously for three years. When you take the oath of naturalization, you must be in the United States.

At present, China nationality can also give you many benefits. Don't do dangerous things just for the sake of the nation. Be careful.