Abstract: In order to improve laser ranging accuracy and frequency of docking guidance system, several aspects were researched on the methods of distance measurement, the influence of the pulse spreading, the received SNR, the receiver bandwidth and the methods of threshold setting. The ranging performance of short-range moving targets was improved by improving the self-triggering pulsed time-of-flight laser ranging method, increasing the peak power of radio signal, using the appropriate filter, reducing the bandwidth of the receiving system and setting the adaptive threshold. Finally, the semiphysical simulation experiment was adopted to test the system-s ranging performance, and the results show that the dynamic ranging accuracy is less than 2cm which meets the design requirement of docking guidance system.