Abstract: Winter is the most difficult period for the prevention and control of atmospheric PM_2.5 pollution, Yichang City has adopted appropriate winter prevention measures for air pollution prevention and control in recent years and achieved certain improvement effects. Yichang City was used to evaluate the effectiveness of emergency control of heavy pollution during the 2021–2022 winter prevention period by analyzing changes in air quality, particulate matter component characteristics, and analytical source changes during the past three years. The results show that the PM_2.5 concentration level was significantly reduced in Yichang City during the 2021–2022 winter prevention period  compared to the previous two winter prevention period; concentrations of NO₃^-、SO₄^2-、POA and SOA were significantly decreased in 2021 comparison to the 2019 winter prevention  period, by 11.8%、12.7%、24.4% and 29.6% , respectively, indicating that the control measures for industrial and mobile sources and domestic sources were effective during the winter prevention period ; the main sources of PM_2.5 during the winter prevention period are secondary sources, motor vehicles exhaust, biomass combustion, industrial sources and dust sources, of which the contribution of motor vehicles decreases year by year, while secondary sources and industrial sources account for an increase in 2021 compared to 2019, mobile sources have a significant control effect, and secondary sources account for the dominant factor ; Using the WRF-Chem model simulation to evaluate the effect of emergency control measures in three typical heavy pollution periods during the winter prevention period from 2021 to 2022,  and its control measures reduced the concentration of PM_2.5 by 4.2% to 9.2%. This study also shows that the trend of compound air pollution in Yichang city is getting worse, and the prevention and control of PM_2.5 becomes more difficult, so it is necessary to further strengthen refined control measures.