Abstract: With the rapid development of domestic heavy\|duty freight trains, there comes tremendous difficulty in effectively testing the braking performance of the air braking system of long formation trains. Based on the similarity of braking of each vehicle and the regular pattern of air wave and braking wave transmission through the whole vehicle, a semi\|physical train braking system simulation platform is established. Based on the braking performance test conducted on a small formation train that adopts typical air brake, the whole train braking and mitigation model is established. Simulation calculation is conducted using gas volume charge and discharge model, and real\|time correction is performed with correction function, which can realize real\|time control of the semi\|physical train braking system simulation platform, laying an ideal mathematical model foundation for establishing intelligent test platform.