can I apply for working visa and for my son s1 at the same time?

Hi, you are advised to contact the embassy directly for more details. As I know, S type requires birth certificate and invitation letter, as well as copies of your residence permit. So it may be a problem if you apply for it at the same time as your Z application.

The employer will send you a government issued Employment Permit and Visa Notification Letter which you must submit with a photocopies with your application. Accompanying family members should apply for new S1 or S2 visa submitting invitation letter from the relative with work Z in China and a 'proof of relationship' i.e. their marriage certificate for a spouse, or birth certificate for a child.