Abstract: This study was concentrated on the Flue Gas Desulfurization(FGD) by waste water from converter.A continuous experiment was carried out to find out the rule of pH,Fe²⁺,and FGD ratio with time.The dissolution ratio of FeO was also tested.Through the simulation experiment,it was found that at the condition of controlling the waste water updating ratio with 4%·min^-1,a sustainable pH with 5~6.5 can be gotten.The FGD ratio can surpass 90% together with stable Fe²⁺ concentration and pH by controlling some of the important factors to proper values.The results of this study set a sound base for the industrial study on this topic.