The rapid development of urban rail transit in our country also puts forward further requirements for its braking system, so it is of great significance to carry out auxiliary design of its braking system and to carry out simulation calculation of its working characteristics. The running time between stations of metro vehicles is generally 2 ~ 4 min, which is in a state of frequent starting and braking. The traction load of metro vehicles is nonlinear, random and time-varying. Compared with other loads in the power grid, subway load has its particularity. ActiveX is used to analyze the traction and braking characteristics of subway trains. The traction load theory of subway trains is studied in detail, the parameters of load modeling are determined, the corresponding effective data are obtained, the corresponding data processing scheme is formulated, and the real-time simulation tool MATLAB is used to simulate the operation of subway trains. The braking energy distribution model can provide theoretical support for various urban rail transit braking energy recovery methods, and can also provide basis for selection of various braking energy recovery devices.