Abstract: Fault detection and condition evaluation are of great significance to ensure the normal operation of EMU gearbox. By studying the feature extraction method and judgment of vibration signal, the differences of vibration eigenvalues such as effective value, peak value, standard deviation, skewness and kurtosis of gearbox vibration under different fault modes and test conditions are compared. The results show that the fault mode of the gearbox of EMU directly affects the vibration eigenvalue; The characteristic value of dimensional vibration is obviously affected by the running speed. The change of the characteristic value is evident under the high running speed condition. The dimensionless vibration eigenvalue is greatly affected by the bearing fault simulation form, but little affected by the running speed. By comprehensively comparing the sensitivity of vibration eigenvalues under various fault state, dimensional eigenvalues are more sensitive to fault than dimensionless eigenvalues