The whole rock and ore mineral magnetite Fe isotope compositions of layered rocks and ores in the Panzhihua vanadium-titanium magnetite deposit of Sichuan Province were analyzed in this paper. The characteristics of magnetite Fe isotope composition demonstrates that the processes of magma complement and fractional crystallization resulted in the formation of the Panzhihua vanadium-titanium magnetite deposit. During the creation of bottom petrofacies, frequent basaltic magma complement formed bulk magnetite with insignificant variation of  δ⁵⁷Fe. The ore-forming oxygen fugacity of the initial magma in Panzhihua was relatively high, and the oxygen fugacity gradually decreased with the magma evolution. The conclusion also reveals the ore-forming mechanism of the Panzhihua vanadium-titanium magnetite deposit in Sichuan Province.