If all requirements for work visa are prepared, it takes 4 working days for the embassy to process the visa application, however, in fact, the organization of all requirements last about a few months.

Your employers needs to provide you the below 2 document for work visa application:
1. Employment Permission
2. visa authorization paper issued by relevant Chinese authorities.
Then you need to prepare the below documents:
1.Properly filled out Visa Application Form, to which one passport-size photo is attached,
2.Valid passport