<p>As one of the most abundant and widely distributed aerosols in the troposphere, dust aerosols act as condensation nucleus to alter the life cycle of clouds and precipitation, thus affecting weather and climate. However, the exact effect of dust aerosols on precipitation, specifically polluted dust, remains to be fully understood and warrants further exploration. Based on raindrop size distribution data in Pudong, Shanghai, China, from 2021 to 2022, two precipitation episodes with polluted dust are taken as examples to clarify the mechanism of the inhibition of polluted dust on weak precipitation. Compared to the dust-free precipitation event, the average concentration of small raindrops increased by 13.8%, while that of large raindrops decreased by 19.2% in polluted dust precipitation event. This may be attributed to the participation of polluted dust aerosols in cloud microphysical processes, which led to the suppression of precipitation efficiency and the significant reduction of large raindrop concentration. However, anthropogenic aerosols have the opposite effect in convective precipitation. It is found that, compared with clean conditions, the average concentration of small raindrops in stratiform precipitation decreases by 63.5%, whereas that of large raindrops in convective precipitation increases by 8.04 times under high pollution conditions. These findings highlight the inhibition effect of polluted dust aerosols on weak precipitation and the promotion effect of anthropogenic aerosols on convective precipitation, which can provide scientific insights for weather and climate prediction.</p>