Infrared polarization radiation of aircraft targets after transmission through high-temperature exhaust plumes is an important basis for infrared detection equipment to detect, identify, track and warn aircraft. At present, most of the studies on the transmission characteristics of gas polarized radiation focus on the visible wavelength band, and the research object is mainly the atmospheric environment. The study of infrared polarization radiation transmission characteristics in the special gas environment of high-temperature exhaust plume is still insufficient. In this paper, the Monte Carlo method is used to model the transmission of infrared polarized light in a high-temperature exhaust plume, and the absorption coefficients of H₂O in 2.5~3.3 μm band and CO₂ in 4~5 μm band are calculated by using the HITRAN database. The multiple scattering process of photons in the exhaust plume space is simulated, and the changes of the cosine of motion and cosine of vibration of the photons in the collision events are analyzed at the microscopic level. Also, the photon characteristics are statistically analyzed based on the principles of the calculation of polarization and transmittance. Based on the simulation results, the changes of radiative transmittance and polarization at different transmission distances are compared, and the effects of exhaust plume temperature, pressure, gas component concentration and detection wavelength on the transmission characteristics of infrared polarized light are analyzed as well. The experimental results prove that the error between the calculated radiative transmittance in this study and the HITRAN database is basically within 2%. The effects of temperature and pressure on the transmission characteristics of polarized light become more and more significant as the distance increases. Pressure is negatively correlated with transmittance and polarization, while the effect of temperature is related to gas type and temperature range. Radiant transmittance and polarization decay exponentially with the absorption coefficient of the gas in the exhaust plume space as well as with the transmission distance. Different detection wavelengths also lead to differences in polarized light transmission characteristics.