As the single photon detection greatly improves the sensitivity of a traditional detector, it has enormous potentiality in distance measuring. Photon-counting laser ranging is able to extract the target's trajectory from large amounts of echo information in the case where prior information is unknown. This paper first provided the simulation of echo information produced by photon-counting laser ranging system, and then extracted the trajectory of the target through image processing. Comparing with the theoretical moving trajectory, the error is less than 5 m. Considering its advantages in short distance ranging, the photon-counting laser ranging system can be applied to the Beidou navigation system and solve its accuracy defects caused by environmental factors while cable patrolling.