The integration of urban and rural areas of social security is an important starting point for narrowing the gap between urban and rural areas of social security, and it is also a key factor in determining the process of urban-rural integration of social security. Constructing an evaluation index system for urban-rural integration of social security from the three dimensions of social insurance, social assistance and social welfare, this paper uses the global entropy method, Dagum Gini coeffi cient, Kernel density estimation and variance decomposition method to multi dimensionally calculate the overall social security and urban-rural integration levels of 27 provinces from 2012 to 2020 and the urban-rural integration level of the three dimensions. The study found that the overall level of urban-rural integration of social security in China is low, but there is a growth trend, and there are obvious regional diff erences, as a whole, the pattern of eastern ＞ central ＞ western, and from the perspective of subsystem, the level of urban-rural integration of social insurance is the fastest, and the level of urban-rural integration of social assistance is the highest; In terms of regional diff erences alone, there is a steady downward trend overall, and interregional differences are the main source of the overall differences in urban-rural integration of social security, followed by intraregional diff erences; From the perspective of dynamic evolution, the main peak position of the nuclear density curve of urban-rural integration of social security in China has shifted to the left, the height of the crest is rising, the width of the crest is constantly narrowing and there is a phenomenon of right tailing, indicating that the absolute difference between urban and rural integration of social security in China shows a signifi cant trend of narrowing, and the absolute diff erence between the eastern and western regions shows a narrowing trend, but the central region shows an expanding trend; The variance decomposition shows that social insurance diff erences are the main source of the comprehensive level of urbanrural integration, and the diff erence in social welfare dimensions after the social assistance dimension contributes the least, but the variance decomposition is not the same in various regions, especially social assistance plays an important role in narrowing the gap between the urban-rural integration structure of social security in the eastern and central regions, and social welfare also plays the same role in the western region. Finally, this paper puts forward relevant suggestions from the aspects of strengthening top-level involvement, strengthening regional cooperation and coordinated development of various systems, which will not only help improve the integration of urban and rural areas of social security, but also help to solidly promote common prosperity and enhance the sense of gain, happiness and satisfaction of the broad masses of people.