Abstract: 75%CaF₂-15%Al₂O₃-10%CaO ternary slag series and quarternary slag series of 60%CaF₂-20%Al₂O₃-10%CaO-10% were used for electroslag remelting to prepare iron based superalloys slag ingot, and the comparison and analysis were made. The results show that the smelting quarternary slag series, Al, Ti elements in the alloy is damaged seriously, the particle size of inclusions is too small, the distribution is scattered, electroslag ingot surface quality has been significantly improved; melting point and conductivity of ternary slag series low and high viscosity, but two kinds of slag the density difference is not significant.