An idea of using laser Doppler velocimeter(LDV) to offer the velocity in vehicle inertial navigation system was proposed. The principles of measuring its own velocity of laser Doppler and relative theory of wavelet transform were expounded. Doppler signal was processed using wavelet transform, simulation and experiment showed that: after signal decomposition, processing the wavelet at each level, acquired good de-noising effect; in common threshold principles of de-noising, rigorous SURE and minimax principles did not lose the useful information easily, but heuristic SURE and fixed threshold principles acquired better de-noising effect; results of frequency extraction with wavelet transform and fast Fourier translation (FFT) were consistent, but velocity and correspondent moment could be a