In order to measure the speed of a projectile accurately and rapidly，a measuring speed radar is often used to process the signals produced by the projectile nose. It is a main method for measuring speed widely used in the world. In the aspeet-of signal data processing，the domestic measuring speed radar lacks some functions and has poor reliability and low speed. So we have developed some measuring speed radars in our shooting range with microcomputer. This paper illustrates how the microcomputer is used to process the radar signals so as to measure the speed of a flying projectile rapidly and accurately.