In order to study the de-noising of laser radar detection echo signal, the laser radar transmitting and detecting echo signal were analyzed based on the wavelet threshold method, and a model based on MATLAB simulation platform was created. The strategy of selecting the parameters in the threshold method was studied, and the best parameters in the denoising were selected combined with the characteristics of the laser radar signal and noise. The simulation experiments of four kinds of threshold strategies were carried out to achieve the effective extraction and denoising of the target signal in the detection echo signal. The results show that, for the low signal-to-noise ratio signal, the higher the decomposition layer of one base function is, the better the denoising effect is. The de-noising effect is the best when the decomposition layer j=4~5. For the high signal-to-noise ratio signal, the lower the decomposition layer is, the better the denoising effect is, the best at j=3. And the denoising effect of the signal db9 base function is better than that of the db2 base function. An ideal denoising result is obtained in this study.