No, you can't! ... by the current regulations!

https://www.travelchinaguide.com/embassy/visa/student.htm

Working on X Visa Is Not Allowed

You are not permitted to work on the X type visa. But part-time work and internships off campus may be authorized. You should contact you university or employer after you have settled in China to see what can be arranged.

For foreign students who work in violation of Chinese regulations or beyond the prescribed scope of jobs or time limit, they shall be deemed unlawful employment and will probably have to stop or be expelled. 

online any kind of work you can do in china it wont effect you just keep it to yourself then no problem.

It appears that the current regulations prohibit working on an X type visa in China. While part-time work and internships off-campus may be authorized, it is essential to contact your university or employer after settling in China to determine what arrangements can be made. Engaging in employment that violates Chinese regulations or exceeds the prescribed scope of jobs or time limits may be considered unlawful, potentially leading to the cessation of employment or expulsion. It is crucial to adhere to the visa regulations to avoid any legal issues.

A student can work from any country depends on what kind of work you want what a you capable of achieving throughout the working period.

Yes, as a student in China, you can work online. There are various online job opportunities available, such as freelance writing, graphic design, programming, and online internships