Abstract: In response to the requirements of wide measurement range, high accuracy, real-time measurement to laser ranging system in aerospace applications, a laser ranging scheme was designed by using dispersed direct phase ranging method. The theoretical measurement range can reach 10 km and the degree of ranging accuracy is within 0.1 m. The laser system, narrow-band filter and the APD photodiode were particularly required by analyzing the space background noise (including space radiation, earth radiation and solar radiation) and range equation for non-cooperative space targets. The experimental results indicate that the maximum ranging error of the system is 8.71 cm, and the system has high dynamic performance with the ranging time less than 1 ms. Moreover, the power consumption and quality of the prototype is small(13.29W and 693 g respectively), which makes the system a suitable payload for space- based applications.