Is it illegal to work part-time without paying social security?

Part-time job, you can not pay social security. Where an employer establishes a labor relationship with a part-time employee, it shall register and pay social security fees for the employee within 30 days from the date of employment.

Legal objectivity:

Article 57 of the Social Insurance Law of People's Republic of China (PRC), the employing unit shall, within 30 days from the date of its establishment, apply to the local social insurance agency for social insurance registration with its business license, registration certificate or unit seal. The social insurance agency shall, within fifteen days from the date of receiving the application, examine and issue the social insurance registration certificate. Article 58 of the Social Insurance Law of People's Republic of China (PRC), the employing unit shall, within 30 days from the date of employment, apply to the social insurance agency for social insurance registration for employees. If the social insurance has not been registered, the social insurance agency shall verify the social insurance premium it should pay. Employees-free individual industrial and commercial households who voluntarily participate in social insurance, part-time employees who do not participate in social insurance in the employing unit and other flexible employees shall apply to the social insurance agency for social insurance registration. The state establishes a national unified personal social security number. Personal social security number is a citizen's identity number.