Infrared effects of created models in this paper are studied via sensor vision and sensor works modules in real-time 3-D emulational software named Vega. The principle of infrared simulation flow is introduced and the simulation results are presented, and then the infrared simulation flow is given. To improve the precision of simulation, some methods are given. In combination with the mapping mechanism of the Vega, a more precise radiation-grey mapping under a far infrared wavelength is presented, meanwhile, a more factual formula of reflectance calculation for materials is obtained by improving the mapping in TMM. Using the established sensor model, the radiation warp is reduced to 1.145%~3.358%. Furthermore, the Verification, Validation and Accreditation(VVA) of the simulation system are discussed, and the creditability of whole simulation process is evaluated, which provides some references for further researches of the simulation systems.