Abstract:In order to extract the instantaneous frequency (IF) of feature component from complex multi-components signals, the component IF extracting method in harmonic wavelet domain was Based on the analysis of harmonic wavelet transform principle and in light`of its excellent properties, the frequency spectrum discontinuity point of harmonic wavelet was smoothed by adding certain windows and the Aiming at the disadvvantages of universal IF estimation, the techiques of resampling were app;oed in the process of deriving instantaneous phase. The sinylation results of synthetic and gearbox fault signals were presented to of verify the feasibility and validity of the method proposed.