Abstract: In order to obtain the dynamic response of the high-speed electric multiple units (EMU) gearbox, the vibration characteristics of the high-speed emu fault gearbox system are analyzed better, and the problem of the shortage of physical samples of gearbox fault and the lack of sufficient verification input signals for the development of the emu gearbox fault detection system is solved. According to relevant parameters, CAD model of high speed EMU bogging-gearbox was constructed, and then imported into Adams/View to build a complete dynamic model of EMU bogging-gearbox. By simulating normal and broke fault conditions, the dynamic vibration response of the test point of the detection scheme is obtained through simulation, after comparing and analyzing the response signal of the gear box, it was found that it's vibration energy will be enhanced due to the fault of broken teeth, and the vibration impact characteristics will occur. The amplitude of meshing frequency will decrease and the edge frequency band will appear. Meanwhile, the extreme point of amplitude will change from meshing frequency to frequency conversion. By studying the vibration characteristics of gear box under the fault of broken teeth, the fault diagnosis of gear box in EMU can be diagnosed quickly, which provides support for the development of gear box fault detection system.