In order to solve the problem that wavelet transform and windowed vibration separation technology are not effective in fault diagnosis of existing planetary gearbox local fault vibration simulation models，a planetary gear local fault vibration simulation model based on gear meshing impact response and gear meshing sequence is proposed. The single meshing impact vibration response of normal teeth and fault teeth is simulated，and the time points of each gear engagement are calculated. The single meshing impact response is used to splice according to the gear meshing sequence. Considering the time-varying transmission path of the vibration signal and the modulation effect of the rotation frequency of the sun gear，planetary gear and planetary carrier，the local fault vibration simulation model of the planetary gear to meet the fault feature extraction of the windowed vibration separation technology is established. The correctness of the model is verified by analyzing and comparing with the simulated and measured vibration signals collected on the planetary gearbox test platform.