Common prosperity requires both “development” and “sharing”. Building a common prosperous society includes not only the dimension of high-quality economic development，but also the dimension of building social modernization. On the basis of understanding the connotation of common prosperity，this report puts forward an index system for measuring the common prosperity level of megacities from two dimensions of economy and society，and discusses the results of the common prosperity level of megacities by analyzing the existing statistical data. It is pointed out that the economic and social development level of megacities is higher than the national level，especially the level of social construction，which shows the high-quality development characteristics of common prosperity in the two dimensions of economy and society. It is also found that there are differences in the level of economic and social development among megacities，and Beijing，the capital，is in a leading position for common prosperity and development. In order to continuously promote the realization of common prosperity，on the one hand，we should continue to give full play to the economic and social development advantages of megacities，drive the economic and social development of other regions through benchmarking，and continuously narrow the regional development differences while realizing the sharing of development achievements；On the other hand，while continuously promoting high-quality economic development，we should pay more attention to social construction investment oriented to social modernization，and promote the all-round development of people as the main body through the coordinated development of economy and society.