As a mega city，the construction of the primary medical and health care system in Guangzhou still faces the problem of unbalanced and insufficient development. The main problems are that the resource allocation structure is not reasonable，the distribution of high-quality medical resources is still unbalanced，the development of medical and health institutions is relatively extensive，and the quality of grass-roots services still needs to be improved. In this context，the “14th Five-Year Plan for the Development of Guangzhou’s Health and Wellness Development” requires more emphasis on resource being allocatized to grassroots level and systematic collaboration，and promotes the transformation from being disease-centered to being health-centered. Based on the current situation and service demands for the development of the primary medical and health system in Guangzhou，this paper analyzes the characteristics of supply and demand and the main contradictions for constructing a primary medical and health system in Guangzhou as a mega-city in the new era from the perspective of supply and demand matching through questionnaires，interviews and other research methods. Suggestions such as consolidating the bottom of the grass-roots medical and health service network，promoting the quality and efficiency of grass-roots medical and health institutions，accelerating the improvement of the hierarchical diagnosis and treatment system，strengthening the training of general practitioners，and strengthening the construction of grass-roots medical and health information.