The agglomeration of population and industries has led to the rapid growth of fossil energy consumption, resulting in the continuous increase of air pollutant emissions and irreversible negative impacts on the regional climate. Based on the multi-source remote sensing data, this paper analyzed the temporal and spatial distribution of Aerosol Optical Depth (AOD) and PM_2.5 in the "2+26" urban agglomeration from 2015 to 2019, and the influence of aerosol optical thickness on PM_2.5 concentration was analyzed by calculating the correlation coefficient. The main conclusions are as follows:(1) The overall change of PM_2.5 concentration was winter > spring > autumn > summer, and it showed highly spatial autocorrelation. From 2015 to 2019, the PM_2.5 concentration has dropped significantly to below 40 μg/m³. (2) The average range of AOD values was between 0 and 1, showing the distribution characteristics of high in spring and summer while low in autumn and winter. By 2019, the concentration of AOD in spring, summer and autumn showed a significant decrease, and was the most significant in summer. AOD also showed a high spatial autocorrelation. (3) There was a significantly positive correlation between AOD and PM_2.5 concentration. From the perspective of seasonal changes, the correlation showed the characteristics of autumn>summer>winter>spring. And the annual average AOD and PM_2.5 concentration showed a moderately positive correlation.Therefore, a quantitative study of the similarity and correlation between AOD and PM_2.5 concentration in spatiotemporal changes can prove the influence of aerosols on air pollution, and provide scientific ideas and basis for future urban air quality management.