Under the leadership of the communist party of China（CPC），during the 13th five-year plan period（2016-2020），many of the original developments targets of China’s social security system have been fulfilled，and some of the tasks have been fulfilled ahead of schedule. The developments are manifested in five aspects. First，institutional framework is constantly improved and integrated；Second，the coverage continues to expand；Third，the social security dimension achieved to full coverage of individual life cycle；Fourth，the level of treatment from basic to moderate sustainable；Fifth，the modernization level of management system and governance has been effectively improved；Sixth，responsibility sharing should realize the transformation to multi-subject. Entering the new era，the development of China’s social security system is also facing new domestic and international challenges. It mainly includes：the downward pressure on the economy has a significant impact on employment and finance；The ability of industrial transformation and upgrading to drive new employment is weak；The acceleration of population aging and the miniaturization of family size；The acceleration of urbanization and the rapid movement of population across areas；New requirements of transnational labor mobility for social security internationalization；Social security is under financial strain. According to the guidance of the fourth plenary session of the 19th CPC central committee，the main suggestions for realizing high-quality and sustainable development of China’s social security system during the 14th five-year plan period（2021-2025）include：First，further to clarify the government’s responsibilities and strengthen bottom-up guarantees；Second，to realize the nationwide coordination of basic endowment insurance as soon as possible；Third，to achieve “population full coverage” of basic social insurance；Fourth，to establish a scientific social security benefits adjustment mechanism；Fifth，to improve the financial sustainability of social security funds；Sixth，to give full play to the role of unemployment insurance in stabilizing employment；Seventh，to promote the transformation of medical insurance from reimbursement to health management and disease prevention；Eighth，to accelerate the pension service system Construction，in-depth advancement of the supply-side reform of elderly care services；Ninth，to establish a demand-oriented family support policy system；Tenth，to actively promote the social security legal system.