A comprehensive emergency medical service (EMS) system significantly enhances a city’s capacity to prevent and mitigate disasters. Using Huangshi as a case study, this research evaluated the service radium coverage rate of the current EMS system by examining its transport capacity, population density, and prevalence rate, finding it to be only 61.49% with an inefficient spatial layout. To address this, we proposed transforming urban brownfields into EMS parks. By selecting the most suitable brownfields based on capacity and service radius, we increased the coverage rate to 90.21%. We introduced a new "consultation-referral" model, where existing EMS facilities serve as pre-diagnosis and triage centers, and the urban brownfield EMS parks function as isolation and centralized treatment centers. GIS network analysis confirmed the feasibility, showing all transit times to be under 30 min. The methodology outlined in this study—comprising "demand assessment, supply optimization, and feasibility verification"—not only strengthens the city’s EMS system but also facilitates the renewal of urban brownfields. This approach can serve as a valuable reference for enhancing EMS systems in other cities.