Abstract: In order to explore the characteristics of particulate matter (PM) removal during two-stage flue gas desulfurization, a Dekati low pressure impactor was used to determine PM concentration at the inlet and outlet of each air pollutant control device of a 300 MW power plant in Xi'an. A sampling system was set up at the inlet and outlet of the desulfurization system for collecting particles to analyze water-soluble ions. The results show that the PM₁₀ removal efficiency in the desulfurization system is 60.3%, and the mass concentration of PM₁ does not show the reverse growth phenomenon. The water-soluble ion contents of SO₄^2-, Cl^- and Mg²⁺ in PM₁₀ increased at the outlet of the desulfurization system. The mass concentrations of PM₁ increased by 24.7% in the selective catalytic reduction system. The removal efficiencies of electrostatic precipitator for PM_2.5-10, PM_1-2.5 and PM¹ were 98.6%, 98.3% and 95.7%, respectively. The removal efficiency of wet electrostatic precipitator was over 60%. The mass concentration of PM emission was 2.89 mg·m^-3 and the emission factor was 0.049 kg·t^-1 under 70% load.