Wavelet transform(WT) with variable time-frequency window can focus on any details of the signal and is suitable for the research and analysis on non-steady state and transient signals,but the presence of wavelet aliasing phenomenon leads to the low accuracy and poor robustness for harmonic analysis. Since the db20 wavelet has the characteristics of high-order vanishing moments and perfect effect for frequency band division,the harmonic analysis method based on db20 anti-aliasing wavelet transform is propos...