The invention discloses an 
infrared vision based automatic landing guidance method and 
system applied to a fixed-wing UAV (unmanned aerial vehicle). The 
system comprises two identical 
image tracking modules, an 
image processing module, a control module and a 
wireless transmission module, wherein each 
image tracking module comprises a camera and biaxial pan-tilt units. According to the method, the UAV is detected, identified and tracked in images with an 
image tracking technology, and deflecting angles of the pan-tilt units are accurately recorded; the 
relative space position of the UAV can be determined through geometric 
relationship analysis and trigonometric calculation of 
pitch heading angles of the two pan-tilt units and the distance between the pan-tilt units, and position information of the UAV is sent to the UAV through the 
wireless transmission module, so that the UAV is guided to accurately land. The 
infrared vision based automatic landing guidance system is constructed on two sides of a landing 
runway of the UAV, complicated 
image processing is performed based on powerful computing capacity of a ground-based computer, each guidance device is utilized to the greatest extent, the accuracy of the 
system is improved, the control is simple, and real-time performance and stability are good.