In the context of smart city construction, medical buildings need to carry more functional requirements, and their detailed design is an important part of building engineering construction. Detailed design often has the characteristics of small fault tolerance, high accuracy, and high refinement in building engineering projects, so the requirements for designers are relatively high. Using BIM technology for detailed design can fully leverage its visual and integrated features and advantages, and improve the quality and effectiveness of detailed design. The article elaborates on the relevant concepts of BlM technology and smart medical buildings. Taking a medical college in Chongqing as an example, it elaborates on the specific application of BIM technology in the deepening design of smart medical buildings from the aspects of design concepts, design difficulties, and implementation plans, providing new ideas and suggestions for the design of medical buildings.