To elucidate the promotion mechanism of the oxidation performance of the Al-W alloy fuel， Al-20W and Al-30W alloy fuels were prepared by the aluminum thermal reduction and the ultra-high temperature gas atomization， and their oxidation process were studied by thermogravimetric/differential thermal analysis， X-ray diffractometer， and scanning electron microscope/energy dispersive spectrometer. The results indicate that Al-20W and Al-30W alloy fuels both contain metastable Al/W alloy phases， and the types and morphology of the Al/W alloy phases transform with increasing temperature. Al-20W and Al-30W alloy fuels have better thermal oxidation performance than pure Al fuel， with complete oxidation at 1300 ℃ and 1500 ℃， respectively， and all oxidation products WO₃ volatilizing. The presence of W enhances the oxidation performance of the Al-W alloy fuels. The promotion mechanism includes： the volatilization of WO₃ provides channels for O₂ to diffuse into the interior of the particles. As an “O atoms transport ship”， WO₃ transports O atoms to the pure Al phase， promoting the oxidation of the pure Al phase. WO₃ undergoes further chemical reactions and ultimately volatilize in a gaseous form， promoting the oxidation of the phase containing W.