in China, the combination of unified account and account is based on pay-as-you-go and fund accumulation system. That is, 8% of salary is put into personal account, and 2% paid by enterprises is used for pay-as-you-go, that is, it is used for unified payment to the retired generation. However, in practice, due to institutional transformation and other reasons, personal accounts are empty, and this part of the money is used to pay the retired generation. Therefore, the current pension system is actually a pay-as-you-go system, not a strict "partial accumulation system". There are two modes of providing for the aged: pay-as-you-go system and fund accumulation system. Simply put, the former is for working people to support retired people, while the latter is for themselves. Pay-as-you-go system is an old-age insurance fund composed of employees' contributions during their employment, employers' or employers' contributions and government subsidies during the same period to pay retirees' pensions, and an annual balance budget is implemented; The fund accumulation system is that workers establish and accumulate individual pension account funds year by year through their own and employers' contributions during their employment, and then pay their pensions with the accumulated pension funds and investment income after retirement, and implement the fund reserve system. The former has the characteristics of mutual assistance and no pressure to maintain and increase value; The latter has complex management and pressure to maintain and increase value, but it can reduce the burden on the government. Pay-as-you-go system embodies the essence of social endowment insurance system, and China chooses the mode of combining unified accounts with individual accounts to mediate the fairness of intergenerational burden.