Abstract: In order to solve coal-fired power plant pollutant emissions, led by the government, ultra-low regulations of emissions of SO₂, NO_x and PM have been continuously implemented. However, the removal efficiency of heavy metals from flue coal fired flue gas is unstable and inefficient in existing purification facilities. To solve this problem, the perforated tray in the wet flue gas desulfurization (WFGD) system is reformed and upgraded. The removal performance of heavy metals including arsenic, selenium and lead in flue gas affected by single and double tray technologies and different spraying intensity is explored on 26000 m³/h flue gas amount pilot-scale test bench, and the removal performance of heavy metals with different concentrations are compared. The results show that the removal efficiency of As, Se and Pb in flue gas by WFGD facility are all greatly improved and exceeds 80% in the double tray upgraded test.