Iron-cobalt–nickel alloys possess excellent electrochemical performance, mechanical propertiesMechanical properties, and oxidation resistance and are widely used in aerospace and high-end medical fields. In this paper Co3O4, Fe2O3, and NiO were used as raw materials, and Fe–Co–Ni alloys was prepared by molten saltMolten salt electro-deoxidation processProcess in NaCl-CaCl2 molten saltMolten salt system at 1073 K. The reductionReduction processProcess was analyzed by thermodynamicThermodynamic calculation to clarify the reaction processProcess. It was found that elemental Ni was preferentially reduced (NiO → Ni); then elemental Co was formed (Co2O3 → CoO → Co); during the electrolytic reductionReduction processProcess, the O2− generated would react with Ca2+ in the molten saltMolten salt and Fe2O3 in the cathode raw materials to form CaFe2O4, and the Fe component was reduced step by step (Fe2O3/CaFe2O4 → Fe3O4 → FeO → Fe), and finally formed Fe–Co–Ni alloys with Ni and Co.