Social security has been paid for 8 years. Is it still useful?

Yes, you can. Social security includes: basic old-age insurance, basic medical insurance, unemployment insurance, industrial injury insurance, maternity insurance and old-age insurance. The minimum payment is required 15 years, and you can enjoy the old-age treatment only when you reach retirement age. This 15 year means "accumulation" rather than "continuity", which means that you can run in between the two, as long as you have accumulated enough 15 years before retirement.

Legal objectivity:

Article 58 of the Social Insurance Law of People's Republic of China (PRC) * * * The employer 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.