Social pooling of basic old-age insurance expenses is an important part of the basic old-age insurance system for enterprise employees, which refers to the system of unified collection (or collection by tax authorities), unified management and unified adjustment and use of old-age insurance funds by social insurance agencies within a certain range. This system was formed on the basis of the reform of the original enterprise employee retirement system. The specific measures are to change the way that enterprises bear the retirement expenses of employees themselves, and to change it into a basic old-age insurance fund that is uniformly managed by social insurance agencies or tax authorities according to a certain payment base and proportion. Pensions for enterprise employees are issued directly by social insurance agencies, or by social institutions such as banks and post offices, or by community organizations. At first, the purpose of social pooling of basic old-age insurance expenses is to balance and reduce the burden of old-age insurance expenses of enterprises and create conditions for equal competition among enterprises. Later, other purposes were added, such as promoting labor mobility and accelerating the formation of the labor market; Ensure that the pension benefits of employees after retirement are not affected by the economic benefits and survival of enterprises. The level of social pooling of endowment insurance expenses was initially implemented in cities and counties, and now it is gradually transferred to provincial pooling.