The structure and operational principle of the analog electropneumatic proportional valve used in the braking system of CRH2 and other EMU were described. By using ANSYS Maxwell software and AMESim software, the proportional coil model and the overall simulation model of the analog electropneumatic proportional valve were established. Five dynamic characteristics such as the input current and output pressure and so on of the electropneumatic proportional valve were simulated. The simulation results were compared with the standard values. The results show that: the simulation model of electro pneumatic proportional valve is correct and reliable. It provides reference for further improving the characteristics of the electro pneumatic proportional valve.