Abstract: The harmonic analysis method based on discrete Fourier transform usually adopts the mode of windowing and interpolation to reduce the influence of frequency spectrum leakage and fence effect.For the frequency spectrum interference from harmonics,inter-harmonics and negative frequency components to the harmonics of concern,a high precision harmonic and inter-harmonic analysis method based on Dolph-Chebyshev windows is proposed.The signal is truncated by DolphChebyshev windows,and the frequency,amplitude and phase are solved through phase rotation and odd point interpolation,which significantly inhibits spectrum leakage.The classical harmonic signal and power harmonic signal are analyzed,and the results show that the proposed method has higher precision on harmonic and inter-harmonic measurement,as well as a certain anti-noise ability.