We proposed a polarized bidirectional reflectance distribution function (PBRDF) modeling method based on the Monte Carlo method to study the light reflection polarization characteristics of the coating surface. First, the Fourier transform was used to complete the three-dimensional reconstruction of the coating-substrate bilayer rough surface. Then, the random process of reflection and refraction on a single facet was solved according to the microfacet theory and the Fresnel equations. Finally, the statistical summation of the polarized light scattering process of the reconstructed surface was made using the polarization ray tracing technique and the Monte Carlo method to obtain the PBRDF of the coating surface. The simulation and experimental results show that the PBRDF established by the method in this paper is correct and has higher precision than the existing models. The rules of the effect of incidence angle, incident light wavelength, surface roughness, and substrate material on the light reflection polarization characteristics of the coating surface were analyzed, providing a theoretical basis for the target detection and measurement of the coating surface.