_{:At present, the production methods of Ti6Al4V alloy powder mainly include atomization method, mechanical alloy method, and hydrodehydrogenation method, but they are still based on the Kroll method to produce sponge titanium. Molten salt electrolytic method and metal reduction method are still in the laboratory research stage. According to the thermodynamic characteristics of step-by-step reduction of high valent metal oxides and the thermodynamic transmutation of different equilibrium phases in the reduction process, a new idea of preparing Ti6Al4V alloy powder by multi-stage reduction of metal oxides (TiO2, V2O5) as raw materials were put forward. Firstly, the Gibbs free energy change of TiO2-V2O5-Mg-Ca system is calculated. The results show that it is thermodynamically feasible to obtain Ti6Al4V alloy powder by magnesium thermal self propagating reaction and calcium thermal deep reduction reaction. Then it is verified byexperiments. After acid leaching of the product of magnesium thermal self-propagating reaction, MgO can be removed to obtain a porous Ti-Al-V-O precursor with an oxygen content of 15.84wt.%.Low-oxygen Ti6Al4V alloy powder(Al: 6.2wt.%, V: 3.64wt.%, O: 0.24wt.%, Mg: 0.01wt.%, Ca: < 0.01wt.%) can be obtained by adding metal Ca in the later stage for deep deoxidation。}