Abstract: Based on the Stokes vector theory, a simulation experiment was carried out by setting up a semi-physical simulation device for polarization transmission to observe the change of the degree of polarization(DOP) of laser under simulated environment(different concentrations of ellipsoidal particles in the non-uniform distribution). In the experiment, the Ganoderma spore carbonized powder was selected as the experimental object of ellipsoidal particles. The ellipsoidal particles were formed into different concentrations of smoke by a fog machine. The change of the degree of polarization (DOP) for linearly polarized light with incident wavelength of 532 nm and 671 nm at 0°, +45°, 90°, and the left-handed circularly polarized light after passing through the simulated environment was studied. Experimental results indicate that the DOP of the incident polarized light shows a downward trend with the smoke concentration increases; the increase of the polarized light of the three kinds of incident light varies with the concentration, and there is no obvious rule to follow; when the smoke of different wavelengths and low concentration is used, the DOP of the linearly polarized light and the circularly polarized light is about the same, about 3%;as the concentration of smoke increases, the DOP of linearly polarized light shows different degrees of decline, up to 20%, and it of the circularly polarized light decreases by only 5%, showing a better polarization maintaining ability.