An algorithm to obtain landing parameters of Unmanned Aerial Vehicle is studied.Five landing parameters including height

side slip distance

roll

pitch and yaw angles can be computed by equations of horizon and edges of runway by image-processing.Basic theory of vision-based measure is introduced.The methods of flight attitude angles estimation were demonstrated in detail.The algorithm of flight height and distance between UAV and midline of runway were presented.The algorithm was verified by landing video of UAV.Experiment showed that this method can obtain five landing parameters effectively and provide landing parameter for UAV.