Abstract: 【Objective/Meaning】By analyzing the challenges and inherent problems faced by the “double reduction” of social insurance under the background of supply-side structural reform, the corresponding measures were put forward to improve the development of social insurance system.【Methods/Procedures】Through literature research, and by combining with the government's policy of reducing fees in recent years and the current status of social insurance rates, the challenges facing the “double reduction”of social insurance were analyzed.【Results/Conclusions】The study found that after the “double reduction” of social insurance, there were some challenges such as the increasing gap in pension income and expenditure, dislocation of target groups and insufficient fund pooling capacity. Therefore, some countermeasures were put forward such as effectively expanding the coverage of insured groups, raising the pooling level of social insurance, establishing a multi-level endowment insurance system, developing commercial insurance, and simplifying and regrouping into “five social insurance and one housing fund”.