The reflection of aircraft skin to background radiation can be used as the radiation source of infrared target recognition,but the background radiation usually comes from the combined effect of solar radiation and ground background radiation,and its complexity and variability may also make the infrared reflection radiation of aircraft seriously interfere with the accuracy of infrared guidance.Therefore,it is of great significance for infrared target recognition and infrared missile guidance to study the infrared reflection characteristics of aircraft skin in complex environment.In this paper,based on the Schlick bidirectional reflectance distribution function(BRDF)model,combined with the finite element method,the radiation shielding factor is calculated by the reverse Monte Carlo method,the atmospheric spectral transmittance is calculated in the MODTRAN software environment,and the infrared reflectance and radiation characteristics of aircraft under different conditions are studied.The results show that different detection angle and detection band have great influence on the infrared reflection characteristics of the aircraft,and the reflection radiation of the aircraft skin has the characteristics of non-uniform distribution.