The smooth operation of the train is one of the important factors of increasing train speed. In order to develop the damping performance that conforming to the hydraulic damper which set in our country’〖KG-*2〗s high speed trains, by made use of the damper online detection system of independent design, the internal damping parameters and the movement parameters of the hydraulic damper in practical operation of the high speed train were tested. The three-dimensional (3-D) model of the damper used in the online detection was established. In ANSYS CFX, by using the dynamic mesh technique to calculate with simulation, the curve of high speed damping characteristic of the damper was obtained. Through comparing results of experiment and simulation analysis, it is proved that the calculation results are correct and reasonable, providing guidance and basis of reference for the damping characteristic optimization design of the damper.