In laser phase ranging,the distance is obtained though the phase of echo signal.Because of spectrum leakage and fence effect,the traditional FFT cannot calculate the phase accurately.Therefore,using frequency spectrum refinement and correction technology to estimate the phase of echo signal is proposed in this paper.Theoretical analyses and experimental results demonstrate that the computing amount of multiple modulation zoom spectrum analysis based on complex analytic band-pass filter is small and the computing speed is quick,while the correction accuracy is the highest.Resolution of frequency spectrum can be improved by frequency spectrum refinement and correction technology,which is very useful in laser phase ranging.The technology in this paper can greatly improve the accuracy of laser ranging in engineering application.