<p>The comprehensive urban carrying capacity is related to sustainable urban development, and it affects urban planning and design. Metropolitan fringe is the main area for urban spatial expansion, characterized by frequent factor flow and complex urban-rural relationships. Its comprehensive carrying capacity research is of great significance. This study examines the acceptance and decongestion of metropolitan fringe based on rapid urbanization development, incorporates regional flow of factors, explores the connotation of “quantity-quality-flow” comprehensive carrying capacity, and constructs a measurement index system. By employing data between 2010 and 2022 from Shunyi District, Beijing, China, this study adopts the entropy method, mean squared deviation method, and obstacle degree analysis method to reveal the level of comprehensive urban carrying capacity and its obstacle factors. Research findings indicate the following: (1) The overall comprehensive carrying capacity of metropolitan fringe is on the rise. (2) The “quality” carrying capacity has the greatest impact on the overall carrying capacity. (3) The “flow” carrying capacity has the maximum contribution on the overall situation. (4) The level of social and ecological carrying capacity need to be improved. The study suggests that in order to enhance the comprehensive carrying capacity of metropolitan fringe, it is necessary to give full play to the advantages of flow and openness, consolidate the foundation of ecological development, enhance the supply capacity of social and ecological resources, and lay the foundation for sustainable development.</p>