Abstract: In the operation process of carbide slag-gypsum wet flue gas desulphurization, problems, such as severe abrasion, high slurry pH value in the tower, hard oxidation of calcium sulfite and difficult dewatering of the vacuum belt dewatering machine, are common in the equipments and the pipelines. In this paper, the carbide slag particle size and chemical composition are analyzed through sampling, and the oxidation of calcium sulfite formed in the carbide slag desulfurization process is studied through tests. The study results show that the physical and chemical properties of carbide slag differ substantially from those of limestone, therefore, the carbide slag-gypsum wet flue gas desulfurization process design and equipment and material selection should not follow blindly the limestone-gypsum wet flue gas desulfurization process. Solutions to these problems are put forward, such as carbide slag pretreatment, reasonable material selection, and separation of SO2 absorption from calcium sulfite oxidation.