You have to cancel the work alien permit. Otherwise the company won’t be able to hire new “foreigners” (they have limited spots). HOWEVER do not cancel your Visa! Do not give them your passport. That means you should cancel the alien work permit (that brownish book) but not the visa on your passport. In your case, since you won’t be coming back to China it won’t make a difference, however somebody who wants to change his job within China must: 1- Cancel the work permit 2- Keep the “cancellation” paper they give you after cancelling the “work permit (it should be pink but the color might change) 3-Do not ever give them your passport to cancel your residence visa
Answering your question: Legally you have to cancel the visa but if you don’t cancel it, you won’t have any problem as long as you leave China before the visa expiration date. Afterwards you can apply to whatever type of visa you want (if you want to come back to China in the future)
