Abstract:When the rolling bearing has a local damage, it will cause the system to produce a periodic impulse, and its vibration signal is often expressed as the form of modulation. In order to be able to accurately and effectively detect the bearing fault, dual tree complex wavelet and energy operator demodulation diagnosis method of combining was put forward. First of all, original fault signals were decomposed into several different frequency components through dualtree complex wavelet decomposition, and the signal of the high frequency modulation frequency band was extracted and used for reconstruction. Then, the reconstruction signal was demodulated by the method of the energy operator. Finally, the characteristic frequency of the fault was extracted accurately by using the instantaneous amplitude spectrum analysis. Through the signal simulation and experimental data analysis it verifies the effectiveness of the proposed method.