In the application of gas in medical treatment, the traditional medical gas supply system has many problems, such as inconvenient pipeline maintenance, easy pollution, safety risks and so on. In order to solve these problems, the modular combined medical gas centralized supply system came into being. This paper makes a thorough research and analysis from the aspects of system composition, design principles and implementation technology, and verifies it combined with practical application cases. The results show that the modular combined centralized medical gas supply system has the advantages of easy maintenance, safety and reliability, energy saving and environmental protection, and is an ideal medical gas supply system.