Abstract: The oxygen content in aerospace-grade vanadium aluminum alloy has an important effect on the properties of downstream titanium alloy materials.Aiming at the problem of high oxygen content in vanadium aluminum alloy prepared by aluminothermic smelting,the occurrence state of oxygen in V-Al alloys was confirmed by thermodynamic analyses.The oxygen in Al V85 preferentially combines with Al to generate α-Al₂O₃and then unites with V to form VO.The oxygen in Al V55 will combine with Al in the alloy to form α-Al₂O₃.The optimum conditions of vacuum deoxidation were obtained by orthogonal tests.At superheat of 60℃,vacuum degree of 1 000 Pa,degassing time of 5 min,argon blowing and stirring for 2 min,the oxygen content of vanadium aluminum alloy can be decreased from 0.15%to 0.009 89%,satisfying the Gf E requirements of aerospace-grade vanadium aluminum alloy.