legal ground
Article 3 of the Interim Provisions on Labor Dispatch
Employers can only use dispatched employees in temporary, auxiliary or alternative jobs.
Temporary work mentioned in the preceding paragraph refers to work with working hours not exceeding 6 months; Auxiliary posts refer to non-main business posts that provide services for main business posts; Alternative work refers to the work that can be replaced by other workers in a certain period of time when the employees of the employer are unable to work due to full-time study, vacation and other reasons.
When the employer decides to use the auxiliary posts of the dispatched workers, it shall discuss with the workers' congress or all the workers, put forward plans and opinions, negotiate with the trade union or the workers' representatives on an equal footing, and publicize them in the employer.
Article 4
The employing unit shall strictly control the number of dispatched workers, and the number of dispatched workers used shall not exceed 10% of the total number of workers.
The total amount of labor mentioned in the preceding paragraph refers to the sum of the number of labor contracts concluded by the employer and the number of dispatched workers used.