Abstract: In order to study the scattering polarization characteristics of cat's eye target echo, a polarized bidirectional reflection distribution function model was established based on the microfacet theory. The degree of polarization of the cat's eye target echo for linearly polarized light was related to target surface roughness, complex refractive index, incident angle and observation angle. The influence of the surface roughness of cat's eye target on the degree of polarization of its echo was studied. The relationship between the degree of polarization of cat's eye target echo and the target surface roughness parameter was obtained by Matlab simulation. The silicon wafers polished by different sandpapers were selected as the cat's eye target. When the root-mean-square heights of silicon wafers is 0.067 µm, 0.554 µm, 0.726 µm, 1.651 µm and 1.893 µm respectively, the degree of polarization of surface echo scattering is 98.83%, 98.16%, 96.08%, 94.91% and 94.6%, respectively. The degree of polarization of cat's eye target echo decreases with the increase of its surface roughness.