This paper introduces experimental results of the ESM of cast iron in the laboratory and pilot plant based on predecessor's work by molten CaF 2-based slag systems containing MgO , CaO and RexOy. The results show that the desulfurization ,inclusion removal and gas elimination of the ESM have obvious effects on making iron liquid purified and producing high quality casting ,and indicate that the ESM of cast iron may essentially improve the traditional process of cast molten iron melting as a new technique for making high quality ductile cast iron.