On the basis of the fact that digital processing algorithm is used by high repetition frequency multi pulse laser rangefinder, the bandwidth of the receiving circuit, the digital sampling accuracy and the filtering algorithm affect the accuracy of ranging. The algorithm of improving measuring precision was put forward by analyzing the error of ranging. Firstly, based on the accumulation of the laser echo signal to improve the signal to noise ratio (SNR), it was followed by the processing of center differential signal, slope threshold condition of echo signal and eliminated the pseudo peak point, thus peak position was determined preliminarily; and then according to the characteristics of the waveform after initial positioning, the corresponding exponential function was selected to modify the waveform of the asymmetric sinc function to obtain the relative exact position of the crest point, so as to calculate the more accurate target distance. Finally, the improved algorithm was simulated in MATLAB, the simulation results show that the proposed algorithm can improve the accuracy of laser range accuracy.