Abstract: UAV (unmanned aircraft vehicle) is a popular platform of the world-s most advanced technology. A scheme was proposed that can be applied to the ultra short wave relay on the pilotless helicopter, and the system-s design, overall structure, working process of the system were explained, as well as the technical difficulties and resolutions met in practice. The most different character between normal relay system and the system this article described is the range of system frequency, the wideband of this system is no less than 200MHz. The signal from long distance can be capable of projecting with the relay, and the dynamic range is on less than 100dB. Weak signal can be detected and the sensitivity of the system is about -100dBm. When there is a powerful signal which is unexpected to receive, a mode called multi-narrow channels can be used to avoid the powerful signal. This system has been tested through a large quantity of experiments, and the statistics show that the relay is capable of projecting long distance signal, and is characteristic of wideband, high sensibility and powerful anti-jamming, and is a qualified system for the need.