Abstract: An infrared radiation model of decoys was built to indicate the characteristics of infrared decoys based on its spatial and temporal distribution characteristics. Then the interaction between infrared decoys and environmental targets was analyzed, and the mathematical model on the reflection characteristics of environmental objectives was established based on bidirectional reflectance distribution function(BRDF), which was used to calculate the radiance reflected by the surface of environmental targets from the infrared decoys irradiance in the observe direction. Finally, a 3D real-time simulation of the ground environment was performed before and after decoys launch. The simulation result showed the effect of decoys radiation on ground environment at different time after decoys launch, which was of great significance for infrared decoys research.