The vibration of railway vehicles is commonly reduced with the use of hydraulic dampers. It is essential for the dampers to achieve the excellent dynamic performance of high speed Electrical Multiple Units (EMUs). Generally, a damper dynamics model is employed to investigate the vehicle system dynamics. Different kinds of damper models would lead to different calculation results of the vehicle dynamics. Therefore, the availability of different damper models on the accurate vehicle system dynamics simulation and damping loads calculation would be investigated. Four kinds of damper dynamics models named simplification model, Maxwell model, a new model presented by Ren and a new model developed in this paper are briefly introduced. The availability of the four kinds of damper models on the vehicle dynamics simulation are investigated. Field test damping forces of two types of high speed EMUs operated in China are presented to compare with the simulation results of the vehicle dynamics with the four kinds of damper models. It is shown that the damper model presented by Ren and the model developed in this paper are all accurate for the vehicle dynamics simulation and damping load calculation. Both the simplification model and Maxwell model have some deficiencies on the vehicle dynamics investigation and damping force calculation.