In this paper,frequency spectrum refinement and frequency spectrum correction method for Doppler signal was proposed separately.Basic principle of frequency spectrum refinement and frequency spectrum correction algorithm was expounded.Spectrum simulation of different frequency ideal sinusoidal signal and real-time Doppler signal were studied based on these theories.Theoretical analyses and experimental results demonstrated that,the Goertzel refinement algorithm has the least computing amount and the quickest computing speed;the ratio correction algorithm for frequency correction has simple correction formula,less computing amount and higher correction accuracy.Resolution of frequency spectrum can be improved by frequency spectrum refinement and correction technology,which is practical useful in frequency spectrum analyzing laser Doppler velocimeter.