The invention provides a wind power gear box fault diagnosis method based on EEMD and generalized S transform, so as to solve problems that a false signal and a false frequency are liable to be generated in a fault diagnosis process in the prior art. The method comprises the following steps: carrying out the measurement of a wind power gear box through an acceleration sensor, and obtaining a vibration acceleration signal x(t); carrying out the decomposition of the signal x(t) through the EEMD, and obtaining a series of IMFs (intrinsic mode functions); calculating and screening an IMFc (IMF component) with the maximum kurtosis value; Carrying out the generalized S transform of the IMFc, and obtaining a time-frequency spectrogram; carrying out the analysis of the generalized S transform time-frequency spectrogram, obtaining an impact period on the generalized S transform time-frequency spectrogram, converting the impact period into a fault frequency, comparing a frequency spectrum analysis result with the gyro frequency of each rotation part of the gear box, and determining the position of a fault. The method can accurately find the position of the fault through the EEMD and the generalized S transform, and irons out the defects that the false signal and false frequency are liable to be generated in the fault diagnosis process in the prior art.