In order to solve the acquisition problem of the multispectral images in the process of the research on Optical-Electronic weapons, a method of generating infrared multispectral simulation images by 3D scene was presented. The infrared image at any observation angle of the scene and a data cube of specific waveband could be generated by the method. Some experiments were done in waveband 3-5 μm to generate a data cube involving 401 infrared simulation images in the wavelength step 0.005 μm. A BRDF calculation model based on the Phong model was derived and used in the calculation of the reflection intensity of solar direct radiation which had strong directionality, and a data cube in waveband 3 -5 μm involving infrared images with directionality was generated when the BRDF calculation mode was applied. The experiments results show that the simulation method presented in this paper could generate infrared multispectral images data cube rapidly, and the BRDF calculation model could reflect the directionality of the reflected light, which improves the fidelity of the simulation images.