Aiming at the theory requirement of the application of infrared polarization information in target detection and identification, the polarization effect produced in the light transmission process of infrared reflectance, thermal radiation, infrared scattering etc. was analyzed and deduced in detail in this paper based on the theory of infrared radiation, and three kinds of polarization effects were modeled and analyzed quantitatively in detail, wherein, the polarization of infrared reflection on object surface was calculated by using Fresnel reflection law, thermal radiation of the object was calculated using Fresnel refraction mechanism combined with the object surface model, and the polarization of infrared scattering on the object surface was calculated by using the Rayleigh and Mie scattering theory respectively. The above conclusion from the study in this paper provides sufficient theoretical foundation for the realization of target detection and recognition by better utilization of infrared polarization information.