You can't. According to the Regulations on the Administration of State Civil Servants, both the Civil Servant Law and the Code of Conduct for Personnel in Institutions require all civil servants not to hold part-time jobs or engage in production and business activities.

Fifty-third civil servants must abide by discipline and shall not commit any of the following acts:

(1) Spreading remarks damaging the reputation of the country, organizing or participating in anti-state activities such as assemblies, processions and demonstrations.

(2) Organizing or participating in an illegal organization, organizing or participating in a strike.

(three) dereliction of duty, delaying work.

(4) refusing to carry out the decisions and orders made by superiors according to law.

(5) Suppress criticism and take revenge.

(six) fraud, misleading and deceiving leaders and the public.

(seven) corruption, bribery, bribery, taking advantage of his position to seek personal gain for himself or others.

(eight) violation of financial discipline, waste of state-owned assets.

(nine) abuse of power, infringe upon the legitimate rights and interests of citizens, legal persons or other organizations.

(10) divulging state secrets or work secrets.