The WRF-Chem model coupled with anthropogenic pollution sources was applied to investigate the impact of anthropogenic pollution on microphysical process and precipitation of a rainstorm occurred on 13 August 2011. Three different simulations including one normal experiment (Experiment Norm) and two extreme experiments (Experiments High and Low) according to the emission intensity of anthropogenic pollutants were conducted. The results showed that the initiation of precipitation was the same in all the three cases. In Experiment Low, the precipitation area remained unchanged while the intensity weakened at the precipitation center but enhanced in the surrounding area, and the intensity of precipitation overall enhanced (weakened) at the initial period (later period). In Experiment High, both the precipitation area and the intensity decreased. Changes in rain water and graupel were the major reason for the change in precipitation. The anthropogenic pollutants could influence the thermodynamic processes of atmosphere through their impacts on the microphysical process, and these changed atmospheric dynamic processes in turn affected microphysics and the growth of precipitable particles. All the above processes contributed to the precipitation change in the ground. The mechanism can be summarized as follows. The atmospheric heating rate decreased due to the decrease in water vapor condensation and ice depositional growth when the emission intensity of anthropogenic pollutants enhanced, and this would cause the decrease in convective activity and suppressed the growth of rain water and graupel, resulting in the decrease in precipitable particles and precipitation reduced eventually.