Abstract: In recent years, the application of Risley prism on the military reconnoiter came to wide attention. The basic configuration and working principle were demonstrated individually, and the troubles on engineering implementation were analyzed. The products at home and abroad were described. The maximal refraction angle of light beam is 10 on Risley prism prototype developed by university of defense technology. Some experiments results show it has realized the scanning imaging function and light beam scanning function preliminarly.