In this case, it is legal for your company to include you in the labor dispatch system, and the labor dispatch employees should also be included in the social security, which will not directly affect the personal social security; However, the overall base of the power bureau is definitely higher than that of the intermediary company, and you may change slightly in all aspects of the payment amount.

The calculation base of social security is related to the overall wage level of the enterprise and the annual wage income of the individual, mainly linked to the personal income (there is a cap on the top and a guarantee on the bottom); So, no matter how your job changes, as long as your income doesn't change much, so does social security.

As for other benefits, that's another matter. As far as I know, many enterprises have little welfare for sending employees. Even though this delicate labor relationship is bound by some new provisions of the Labor Contract Law, many enterprises still try their best to transfer the labor relationship of this part of workers to intermediary companies to avoid the situation that they need to sign "open-ended labor contracts" after continuous employment 10 years; But this transfer of labor relations is indeed guaranteed by law ~ ~ ~

In any case, employers are always in a strong position, and workers can only use their own strength to safeguard their rights and interests.