The wage level of large central enterprises is between foreign enterprises and local state-owned enterprises, far above private enterprises. In particular, the welfare is rich, and many places continue the previous traditions, such as housing and Chinese New Year holiday fees.
There are two identities: career and enterprise. After the reform of personnel system in central enterprises, employees with professional status have also participated in most social insurance, and endowment insurance is being reformed. Some institutions have not yet participated in endowment insurance and other social insurance. The social security withholding ratio is the same as that of local governments, and the most favorable ratio for employees is adopted in calculation. All corporate identities are included in the social security system.
I don't know what you really want to know, so make a reference.