In order to study the process and causes of air pollution in Handan City, we measured the inorganic ion and carbon component to analyze the variation characteristics of PM_2.5 from samples taken at the site of Environmental Monitoring Center of Handan was selected to sample the PM_2.5 concentrations and measure the inorganic ion and carbon component. The air quality model of WRF-CAMx was used to simulate and analyze the PM_2.5 mass concentration contribution of different emission sources in various regions during three heavy pollutions in autumn and winter of 2017~2018. The results showed that water-soluble particles accounted for 62.4% of PM_2.5 mass concentration in Handan during heavy pollution. The secondary ions showed a trend of NO₃^- > SO₄^2- > NH₄⁺. During the three continuous heavy pollution processes in Handan City, the pollution was affected by the ground uniform pressure field, the bottom of high pressure and the zonal circulation of 500hPa at high altitude. The horizontal and vertical transports of pollutant were inhibited. The decrease of boundary layer height further resulted in the increase of PM_2.5 mass concentration. The three heavy pollutions were completely removed with the southward move of Eastern Siberia high pressure and Eurasian Continental high pressure and increase of the boundary layer height. The results of PSAT tracer module showed that the Fuxing District, Congtai District and Yongnian District were the main districts and counties contributing PM_2.5 in Handan City, with the total contribution ranging from 66.8% to 72.2%. The metallurgy, mobile source and residential bulk coal combustion were the three major pollution sources during the heavy pollution period.