Abstract: In order to decrease the measuring error of signal processing in laser Doppler velocimeter(LDV), frequency spectrum correction methods for laser Doppler signal were proposed. Basic principles of energy centrobaric correction, ratio correction and phase difference correction were expounded. The three methods processing ideal sinusoidal signals was simulated with different signal frequencies, and so was the ratio method processing sinusoidal signals with different noises and signal-to-noise ratios. The results show that, all the three methods can effectively correct the frequency, the energy centrobaric correction has the lowest precision, and the ratio correction is the fastest and its precision is almost not affected by the change of signal-to-noise ratio. The ratio correction was applied