Abstract: Interruption exception occurred to the uplink and downlink of UHF and C link of an unmanned aircraft. The failure cause and mechanism were analyzed based on the working principle of the stadia line. It is found that the failure causes include the existence of regional interference signal, the defection of OFP software of task management system, the wrong use of directional antenna servo in emergency disposal. Finally, improvement measures were taken to solve the problem of the interruption exception of the stadia link, and the emergency disposal system was perfected.