Abstract: Based on the structural problems and reform directions of China’s present multi-level pension insurance, it is believed that the national annuity system can find a perfect balance between the stock reform and incremental reform of the basic pension insurance system integration. Comparing the differences between the supplementary national pension system and the welfare based national pension system, in the future, China’s national pension system should implement a welfare based national pension system, committed to providing compulsory and income independent universal pension security for all citizens. By establishing actuarial models and conducting numerical simulations, it is found that the construction of the national pension system can achieve the goal of promoting the integration of urban and rural basic pension insurance systems, covering basic pension security to the whole population, and promoting government financial support to reduce costs and improve efficiency. In addition, the national pension system also helps to solve the problem of pension security for flexible employment groups, narrow the gap between urban and rural pension insurance benefits, provide more efficient pension support models for government finance, and promote a more fair and sustainable development of a multi-level pension insurance system.

Key words: national annuity, basic endowment insurance for urban employees, basic endowment insurance for urban and rural residents, national pension security