Longitudinal force has become an important index to evaluate synchronous control performance of heavy haul train. Mathematical model and simulation model based on Matlab/Simulink of train’s longitudinal dynamics was established. Longitudinal force of 10 000 t heavy haul train under different marshaling and different working conditions was calculated and compared to test data, which verified the feasibility of simulation model; simultaneously, it was proved that the combined train of synchronous control had more advantages in dynamics performance than the traditional train. All of above provide simulation platform and theoretical basis for further analysis and optimization of train synchronous control.