Abstract: Population aging is the key to the sustainable development of the basic old-age insurance system.Based on age shift algorithm and life table technology,this paper makes use of the data of Chinas sixth and seventh national population censuses to calculate the size,years and fund size of Chinas elderly population receiving pensions from 2010 to 2030.The study concludes that due to the increase in the number and proportion of the elderly population and the expansion of pension insurance coverage,the scale of Chinas elderly receiving pensions continue to expand,from 123 million in 2010 to 332 million in 2030.Meanwhile,as Chinas pension level is still increasing,the result is that the payment burden of pension is increasing sharply,and the total expenditure will rise from 1 329.390 billion yuan in 2010 to 11 893.319 billion yuan in 2030.In addition,due to the extension of the life expectancy,the length of pension for the elderly continues to increase,from 10.13 years in 2010 to 19.92 years in 2030,and the growth rate of receiving years has exceeded that of remaining life.Additionally,there are significant gender and urban-rural disparities in the burden of pension payments.Finally,this paper proposes the implementation of measures such as enforcing the delayed retirement policy,cautiously increasing the replacement rate and level of pension,developing a multi-pillar pension system,and encouraging childbirth as measures of structural reforms.These initiatives aim to promote common prosperity in the context of high-quality development of population and economy.

Key words: population aging, pension burden, delayed retirement, common prosperity