Abstract：Small and medium-sized cities are important carriers to promote new urbanization and achieve common prosperity. On the basis of clarifying the relevant concepts of small and medium-sized cities and estimating the number of small and medium-sized cities in China，this report summarizes the contribution of small and medium-sized cities to socialism with Chinese characteristics，analyzes the opportunities and challenges faced in the development of small and medium-sized cities by combing their development history and status quo. Take the top 100 counties and cities and top 100 districts as samples，this report analyzes the development paths of the stars of small and medium-sized cities which provides experience enlightenment for other small and medium-sized cities to better cope with opportunities and challenges. On the basis of the above analysis，the report looks forward to the future and puts forward the development strategies of small and medium-sized cities under the goal of common prosperity.