A new method of signal processing is proposed in this article in order to eliminate the noise interference and enhance the measurement accuracy of laser Doppler velocimeter (LDV). The least mean square (LMS) adaptive filter technology, the frequency spectrum zooming and frequency spectrum correction technology are applied in the signal processing system. Basic principle of LMS adaptive filter and frequency analysis algorithms were expounded first, then spectrum simulation of ideal sinusoidal signal and experiment test are studied based on these algorithms. The simulation and experiment results indicate that the LMS adaptive filter technology has effectively improved signal to noise ratio and minish the interference of noise; Resolution of frequency spectrum can be improved by frequency spectrum zooming technology and the accuracy of signal processing can be greatly improved by frequency spectrum correction technology. It can obviously increase the frequency spectrum resolution, and improve the measurement accuracy for 2~3 times.