Aiming at the vibration signal characteristics for asynchronous motor fault diagnosis，the method combining kurtosis, wavelet denoising and resonance demodulation analysis is proposed. We consider four types of motor states including the normal state, the incomplete open state of centrifugal switch, the chamber swept state, and the rear bearing damaged state, and collect the corresponding single-phase asynchronous motor samples for tests. NI CompactRIO is used to acquire the vibration signals at the side and top of the front cover for each motor. The kurtosis statistical analysis is firstly performed, and wavelet de-noising and resonance demodulation analysis are combined to extract the frequency domain characteristics for each failure type. The tests demonstrate the effectiveness of the proposed approach in the fault diagnosis of asynchronous motors.