The error sources of pulsed laser range finders are analyzed and the factors which have influences on the random error of a pulsed laser range finder are primarily considered. It is found that improving the time resolution of a TDC, using a high speed threshold discriminator chip and reducing the rising edge of a pulsed signal are the effective methods for improving ranging precision. Among them, the reduction of a pulsed signal can be realized by using a narrow-pulse laser and a receiving circuit with a properly designed bandwidth. Simulation shows that the minimum bandwidth required to keep a 5ns rising edge from extending is 90MHz. Then, a high-precision laser range finder is designed and tested. The test result shows that the system has a single-shot precision (3σ) from 0.077m to 0.117m for the targets at different distances within 500m and has a precision better than 0.1‰D+0.05m (D stands for the distance) for the targets at different distances from 500m to 3km. Compared with the formerly designed systems using different lasers and different bandwidths, this system has obviously improved its single-shot precision.