In order to improve the accuracy of long-distance speed measurement, a signal processing method based on wavelet decomposition reconstruction (WDR) combined with fast Fourier transform (FFT) was adopt in this paper. Theoretical analysis and experimental verification were carried out, and the pulse coherent velocimetry data of hard targets at different speeds were obtained. The results show that the targets with a velocity change of 0.02 m/s can be accurately resolved by using the WDR & FFT method. This research provides a reference for the high-resolution velocity measurement of long-distance and low-velocity targets.