Aiming at the problem that the semi-empirical model in the aerosol fine particle retrieval algorithm on the directional polarimetric camera(DPC) platform carried by the GF-5 satellite is not suitable for the estimation of urban surface polarization reflectance. In this paper, based on the empirical orthogonal function method of DPC, the inversion of the optical thickness of aerosol fine particles is carried out. The aerosol radiative contribution is calculated based on Mie scattering, the surface contribution is calculated by the empirical orthogonal function method, and the optical thickness of aerosol fine particles is inverted by using the multi-angle polarization data and the vector radiative transfer equation. The inversion results of this study are consistent with the moderate-resolution imaging spectroradiometer distribution trend of aerosol fine particle optical depth products, quantitatively compared with the measurement results of AERONET Beijing, Xianghe, and Hong Kong stations, the correlation coefficients are 0.97, 0.96, and 0.9, the mean absolute error is 0.08, 0.07, and 0.12, and the root mean square error is 0.12, 0.11, and 0.17, which verifies the high precision and rationality of the algorithm. Finally, the monthly average data of aerosol fine particle optical thickness in some areas of China in 2019 are presented, and the changes of aerosol fine particle optical thickness in Shandong are analyzed. It is found that June is the highest period of the year, with an average value of 0.7. The above results verify the reliability of the algorithm and provide technical support for DPC to effectively monitor the spatiotemporal distribution of aerosols