Based on Vega, a simulation research on IR target imaging is developed. IR radiation models of aircraft skin, exhaust nozzle and flame are analyzed respectively. Incorporating with the IR radiation models, the design flow of IR target imaging simulation are introduced in detail by using some simulation tools such as Vega three-dimensional view simulation tool, texture material mapper (TMM) tool, mosart atmospheric tool (MAT), Creator three-dimensional modeling tool and VC++6.0 developing tool. And IR target simulation images are given. It provides references for similar IR imaging systems.