This project is the flue gas desulfurization project of the side-blown furnace and the fuming furnace in the lead smelting technology upgrading and transformation of Jiuhua Smelter. The lead smelting of Jiuhua Smelter adopts the three-smelting process of bottom blowing furnace→side blowing furnace→smoke furnace, with an annual output of about 52,300 tons of crude lead and 10,600 tons of secondary zinc oxide. The by-product sulfuric acid is about 51,700 tons/year, and the flue gas from the side-blown furnace and the flue gasifier is fed into the desulfurization system to remove the sulfur dioxide in the flue gas and then discharged up to the standard. The desulfurization system adopts the zinc oxide desulfurization process, the tower tank is made of glass fiber reinforced plastic, the desulfurizer is the secondary zinc oxide produced by the flue gas furnace, the control system adopts two control methods of local and DCS, and the products after desulfurization are returned to lead and zinc smelting System recycling. The total flue gas volume entering the desulfurization system is 62688Nm3/h, the flue gas temperature is 120°C, the average SO2 concentration is 3418mg/Nm3, and the maximum is 7500mg/Nm3. It is emitted from the chimney at the top of the tower with a height of 50 meters, and the designed emission concentration of SO2 is less than 200mg/Nm3. The project was signed in August 2017, the construction was completed in June 2018, the commissioning operation in August 2018, and the third-party measured emission concentration was 12.4mg/m3.