Abstract: As the safety net of people's life and the stabiliser of social operation, the development and evolution of the social security system has always been closely related to the "state". The social security model formed by western developed countries by giving full play to the role of the state in their local conditions is intrinsically reasonable, and its useful practice of designing and constructing the social security system by using the power of the state has a pioneering and inspiring effect on China's new era of "perfecting a multi-level social security system that covers all the people, integrates urban and rural areas, is fair and uniform, safe and standardised, and is sustainable". Its useful practice of using national power to design and build a social security system is a revelation for China in the new era to "improve the multi-level social security system that covers all people, coordinates urban and rural areas, is fair and uniform, safe and standardised, and sustainable". In order to optimise China's social security system in the new era, it is necessary to give full play to the role of national legislation to improve relevant laws and regulations and promote the development of social security under the rule of law; to give full play to the role of national administrative regulation and promote a steady increase in the level of social security; to give full play to the advantages of the socialist system and promote the development of the construction of a multilevel social security system; and to deepen the reform of the operation and supervision system and mechanism and promote the optimisation of the effectiveness of social security.