"China has built the largest social security system in the world. We should continue to make efforts to promote the high-quality development of social security, enhance the unity and standardization of the system, develop a multi-level and multi pillar old-age insurance system, and bring more people into the social security system.". Social security is the basic institutional guarantee to ensure and improve people's livelihood, safeguard social equity and enhance people's well-being. It is an important institutional arrangement to promote economic and social development and realize that the broad masses of the people share the fruits of reform and development. It is a major issue in governing the country and stabilizing the country. In China, great progress has been made in the reform and construction of social security system, but there are still many defects in the current social security system and policies. It is necessary to deepen the reform, optimize the allocation of resources and build a higher quality social security system. 1、 Optimize the structure of social security system After the founding of new China, the well-being of people's livelihood has been improved and the guarantee of people's livelihood has been strengthened. Since the 18th CPC National Congress, new progress has been made in the reform and construction of the social security system, and the social security system has become more sound. From the perspective of the new requirements of solidly promoting common prosperity and comprehensively realizing the modernization of the country, the current social security system needs to be optimized from both horizontal and vertical aspects. From a horizontal perspective, we should deeply analyze the basic risks of social members according to the economic and social reality and development trend, so as to form a more complete basic security system, so as to weave a dense network system of social security. First, in order to adapt to the trend of population aging, aging and family miniaturization, practical methods should be adopted to establish and improve the long-term care and security system for the whole people and urban-rural integration, so that the disabled and mentally retarded elderly and their families can purchase basic socialized care services, so as to make this special group with difficulties have basic dignity. Second, expand the protection rights and interests of occupational injury to all workers, improve the design of industrial injury insurance system, establish an occupational injury protection system suitable for formal and informal employees, and actively create conditions to gradually bring farmers into the occupational injury risk protection system. Third, expand the employment security system from cities and towns to rural areas, so as to establish an employment security mechanism suitable for farmers, provide employment assistance to farmers, and enhance their ability to adapt to modern agriculture or enter the secondary and tertiary industries for employment. Fourth, realize the transformation of child welfare from special group welfare to universal welfare, accelerate the establishment of child allowance system and infant care service system, and gradually reduce the family burden of middle-aged and young people in childbirth, parenting and education. From a vertical perspective, it is necessary to further clarify the scope of responsibilities of various basic security projects, especially the degree of security, so as to optimize the hierarchical structure of social security. Social security can be divided into basic security and supplementary security. The former is organized and implemented by the government according to law to ensure the basic survival, basic development and basic dignity of social members, while the latter is the independent, voluntary and self funded behavior of some social members, so that they can have more adequate security on the basis of basic security, so as to live a happier life. The combination of basic security and supplementary security constitutes a multi-level social security system. At present, the prominent problem is that the structure of basic guarantee and supplementary guarantee is not perfect, and the development of supplementary guarantee is slow. Therefore, we should abide by the principle of "ensuring the basic", maintain the moderation of the treatment level of various basic security projects, and make social members have rational expectations for the basic security treatment, so as to enhance the internal driving force for middle and high-income groups to participate in and obtain supplementary security. 2、 Improve the design of basic security system The basic security items in the social security system are set up based on the basic risk protection needs of social members, which aims to protect the basic rights and interests of citizens. Therefore, they belong to the basic responsibility of the government and the category of national basic public services. This is a kind of long-term basic institutional arrangement, which is organized and implemented by the government relying on the force of the state. Moreover, the positioning and system design of this kind of system are not only related to the effective implementation of the basic security rights and interests of social members, but also related to the healthy development of supplementary security. However, the history of the establishment and operation of China's modern social security system is not long. At the same time, important changes have taken place in its operating environment. Therefore, there are inevitably some problems, such as the lack of fairness, worrying sustainability and low operating efficiency of some basic security items in the current social security system. Therefore, there is an urgent need to improve the system design, especially to enhance the anti-poverty function of the social security system Mutual assistance and adaptability to economic and social development. Basic security is the basic institutional arrangement of the country's anti-poverty. After long-term efforts, China has solved the problem of absolute poverty, and many projects in the current basic security system have made important contributions to it. In the future, we should not only consolidate the existing anti-poverty achievements, but also solve the problem of relative poverty. The basic security system will play a more important role, so we need to further improve the system design. First, optimize the allocation of medical security resources, devote more resources to the guarantee of medical expenses for major and rare diseases, and form a sound mechanism. Second, actively explore the integration of basic medical insurance and medical assistance system into basic medical security system. On the basis of clarifying its scope of responsibilities, gradually realize the transformation of medical expenses from the responsibility capping system of basic medical security fund to the individual payment responsibility capping system, so as to fundamentally solve the problem of poverty caused by illness and returning to poverty due to illness. Third, steadily improve the level of security treatment of the basic old-age insurance system for urban and rural residents, and raise the level of financing accordingly, so that it can truly assume the responsibility of preventing poverty among the elderly, and gradually narrow the gap between the basic pension of elderly farmers and retired workers. The social security system, especially the basic security items, are designed based on the principle of mutual assistance, so it is bound to produce a positive effect of income redistribution. To this end, we need to gradually increase the mutual aid gene designed by the system of basic security projects. The current focus is: first, in view of the existence of large-scale low-income groups with weak payment ability in China at this stage, we should appropriately add non payment social security projects on the premise of maintaining appropriate standards, so as to enhance their mutual aid and popularization. Second, gradually weaken the personal accounts in the basic medical insurance and basic old-age insurance system for employees, enhance the insurance attributes of various social insurance items, and cultivate the awareness of mutual assistance and mutual assistance of social members. Third, actively create conditions, timely promote the integration of the two basic medical insurance systems for urban and rural residents and employees, gradually form a unified basic medical insurance system for the whole people, timely promote the integration of the two basic pension systems for urban and rural residents and employees, and gradually form a unified basic pension system or national basic pension system for the whole people. The basic security system is an important part of the national governance system and must effectively adapt to the economic and social reality and development trend. First, in view of the reality of the development of digital economy, the increase of informal employment and the change of labor relations, we should improve the rules for employees' social insurance participation and payment, so that all kinds of salaried workers can smoothly enter the employees' social insurance system and make the social insurance system effectively adapt to the changes of the labor market. Two, in view of the increasing reality of separation of households and households, the household registration degree of social assistance, social welfare and social insurance system is gradually reduced, so that non registered residence residents can enjoy various social security in their registered residence. 3、 Innovating the operating mechanism of social security Social security is related to the vital interests of every social member. It requires every social subject to have a clear responsibility orientation and fulfill their duties, so that the social security system can operate effectively and achieve its policy objectives. After years of practice and exploration, China has formed a set of social security operation mechanism and played a positive role. At the same time, it should be noted that the operation efficiency of this system needs to be improved, especially in the management of social security fund and the supply of relevant services, so as to form a more effective social security operation mechanism. Social security fund management is the core part of the social security operation system, which involves treatment, financing, fund balance and supervision mechanism. Current priorities: first, establish an overall coordination mechanism for the basic guarantee of the guarantee treatment of various projects, gradually unify the basic guarantee system and policies, and strive to reduce or even avoid contradictions among systems, policies, regions and groups. On this basis, according to the idea of "suppressing peak and filling valley", strictly control and gradually narrow the gap of basic guarantee treatment between groups, and put forward a clear schedule and corresponding policies and measures. Second, improve the multi-channel financing mechanism of basic security, and clarify the investment responsibility or proportion of finance, employers and social members in each project. We will improve the rules for the collection and payment of social insurance premiums, implement a unified method for determining the payment base, and standardize the behavior of various subjects related to the collection and payment. The third is to establish the principle of "fixed income based on expenditure" of social insurance fund, establish social insurance actuarial system, scientifically determine social insurance premium rate, regularly analyze the operation of social insurance fund, and establish an early warning and monitoring system for the operation risk of social insurance fund. Fourth, improve the supervision mechanism of social security funds. We will severely crack down on fraud, insurance fraud, arbitrage and misappropriation of all kinds of living security funds, and keep every "pension money" and "life insurance money" of the people. Fifth, establish an evaluation mechanism for the realization of the policy objectives of the social security system and relevant policy simulation and decision-making analysis mechanisms to assess the risk of major policies in the field of social security. The supply of social security related services and its price mechanism are also very important. Many people believe that social security is only a kind of financial security. In fact, some social security projects can achieve their institutional objectives through financial payment, such as minimum living security benefits, basic pensions and various subsidies. However, a considerable number of projects need effective services to achieve their institutional objectives, and these services and their supply subjects have many types and huge business volume, This is a complex operation system, so it needs a set of effective operation mechanism. The current focus is to deepen the reform of the supply mechanism of medical services related to social security, improve the cooperation mechanism between administrative departments such as medical security, occupational injury security and maternity security and their agencies and medical service institutions, including negotiation and consultation mechanism, and effectively regulate the practice behavior of medical personnel related to social security through a series of regulations such as the code of conduct of medical insurance doctors. Second, actively explore the reform of payment mechanism of relevant medical services in the field of social security, such as DRGs (i.e. classification related to (disease) diagnosis), gradually form a scientific and reasonable medical service price formation mechanism based on market pricing, and coordinate with the overall reform of medical services. Third, improve the circulation system of drugs and consumables, and gradually form a circulation mechanism to reduce the intermediate cost of the circulation of drugs and consumables through the exploration of classified procurement and volume procurement. Price drugs and consumables in an orderly manner according to the cost and competition of similar drugs and consumables, and promote the healthy production of similar drugs and consumables. Fourth, accelerate the development of care services for the disabled, establish and improve the needs assessment mechanism for care services for the disabled elderly and the disabled, and promote social development