Abstract: Based on the infrared radiation theory,some factors such as self-radiation,reflection radiation and long wave radiation of the atmosphere were considered. The simulation method of infrared radiation characteristics of the target and the infrared radiation simulation software of object were studied. With a steel plate as an example, the simulation of the target was modeled, and the surface boundary conditions of object was determined. Through the surface temperature field of the target calculated, the temperature data of the steel plate calculated by simulation was compared with the data measured by test. The results show that the average error of simulating calculation is less than 1.5 ℃, it verifies the correctness of the simulation method. Based on the simulation software, the distribution of infrared radiation characteristics of the target in different time is calculated. The rationality of infrared simulation method is proved, and it lays the foundation of infrared simulation of vehicle and complex background.