Abstract: The intermediate link of converting electrical energy into air pressure energy in metro train air braking system might limit the further improvement of braking response speed and control accuracy. In this paper, the application of electro-mechanical braking technology to metro train is discussed, which directly uses electric energy to drive the friction pair for metro train. The composition principle and system scheme of electro-mechanical braking system are introduced, the application characteristics of which are analyzed. Compared with the air braking system, the electro-mechanical braking system simplifies the system structure, improves the system reliability, and therefore can realize the distributed design, full electrification and high intelligence of metro train breaking power source, braking control and execution.