Abstract: Wet electrostatic precipitator （WESP） is a fine treatment equipment for the treatment of coal flue gas.Taking a 660 MW ultra-low emission unit as the research object,the multi-pollutant removal performance and energy efficiency parameters of WESP were tested and analyzed systematically.The removal efficiencies of particulate matter,fog drop,SO₃ and Hg of WESP were 81.12%,75.60%,76.13% and 53.08%,respectively,and the power consumption was 402.6 （kW·h）/h,which met the design requirements.The emission mass concentration of each pollutant were 4.20,17.25,9.80,4.08×10^-4 mg/m~3,respectively,the emission factors were 13.76,56.49,32.10,1.34×10^-3 g/（kW·h）,respectively,the specific power consumption was 1.48×10^-4 （kW·h）/m~3.The energy consumption for particle removal per unit mass was 22.87（kW·h）/kg,which was in the industry average level.This study can provide reference for the subsequent pollutant reduction and energy efficiency control of coal-fired power plants.