Abstract: Aiming at the influence of particle concentration on the laser transmission process in the atmospheric environment, taking the oil mist particles as the research object, the semi-physical simulation experiment of polarization laser transmission was carried out by using the inhomogeneous environment generated by the oil mist particles during the diffusion process. In the experiment, 532 nm lasers were used to study the polarization state variation of horizontal linearly polarized light, 45° linearly polarized light and left circularly polarized light during oil mist diffusion. The diffusion environment was quantitatively calibrated using the particle size analyzer. The experimental results show that the higher the concentration is, the greater the randomness of the change of polarization, and the polarization-maintaining ability of the circularly polarized light is better than that of the linearly polarized light. At the same concentration, the polarization-maintaining ability of 0°linearly polarized light is better than 45 ° linearly polarized light. In the case of extremely high concentrations, when the volume concentration is 2 mg/L or above, the linearly polarized light tends to coincide with the retention of circularly polarized light.