The flue gas desulfurization system is widely used in electric power, metallurgy, building materials, chemical industry and other fields. The desulfurization absorption tower is prone to produce a large number of small droplets during operation. The small droplets not only contain water, but also dissolve sulfuric acid, sulfate, sulfur dioxide, etc. If it is not properly resolved, any "fog" entering the chimney actually discharges solid particles and sulfur dioxide into the atmosphere, and also causes pollution and severe corrosion of the fan, heat exchanger and flue. Therefore, the net flue gas must be defogged before leaving the absorption tower. Therefore, the demister is a key equipment in the flue gas desulfurization system, and its performance directly affects the reliable operation of the wet desulfurization system and the environmental protection indicators of coal-fired power plants.