Abstract: The cementitious materials were prepared with steel slag, blast furnace slag and desulfurization gypsum and its stabilization effect on Cd²⁺ was studied. The results showed that the cementitious materials had a better adsorption effect on Cd²⁺ when the concentration of Cd²⁺ was not higher than 30 mg/kg. The reasons were as follows. Cadmium ions could replace Ca²⁺ into the lattice of ettringite (AFt) and Friedel salt by a "quasi-homogeneous" manner. Then it formed a cadmium-containing double salt and was solidified. Coupled with the adsorption of C-S-H on cadmium, Cd²⁺ was finally cured efficiently. The research results have great significance for the treatment of wastewater containing cadmium.