In the context of global climate change and the rapid development of the sports industry, increasingly frequent flooding has become a significant challenge for Chinese cities today and one of the hot issues in risk management for sports events. In order to reveal the impact of flooding on the spatial accessibility of emergency response to stadiums in the central urban area within the outer ring of Shanghai, this article evaluates the accessibility of medical emergency services in the central urban area under the impact of flooding based on flood scenario simulations and GIS network analysis. Results show that under the different flooding scenarios, as the intensity of flooding increases, urban road traffic in flood-prone areas is blocked by ponding, and some stadiums are inaccessible to emergency vehicles. The scope of emergency response services for some medical institutions along the Huangpu River is significantly reduced, while emergency response times for stadiums in the riverside area are delayed considerably. Some stadiums are unable to access emergency medical services. The study’s results can offer a case reference for upgrading the level of emergency management of stadiums under urban-scale flooding and optimizing the quality of regional medical emergency services.