In this work, a rigid-flexible coupling dynamic model has been established to describe a specific type of locomotive traction drive system, by a parametric modeling method utilizing Creo, ANSYS, and RecurDyn software systems comprehensively. The dynamic characteristics, stress, and deformation results of the system under various working conditions were obtained through dynamic simulation and modal analysis. These results enable the prediction of contact fatigue strength of driving gear tooth surface for the estimation of its service life. On the basis of theoretical analysis, combined with laboratory bench performance tests, the working condition of the tooth surface of the test tooth pair under equivalent load conditions was tested, and it was found that the location of tooth surface pitting was consistent with the simulation analysis. Through the dynamic simulation and fatigue life prediction of the transmission system, it provides a theoretical basis for reasonably improving the efficiency of transmission system parts and setting up the inspection and maintenance cycle.