Abstract: Fe-Cr-Si alloys material has good abrasion resistance, corrosion resistance and high temperature oxidation resistance, especially the introduction of Cr and Si element can furtherly improve its high temperature oxidation resistance.Fe-Cr-Si alloys was designed and prepared by arc furnace process and the microstructure and oxidation behavior of Fe-Cr-Si alloy was investigated by X-ray diffraction(XRD), scanning electron microscope(SEM).The results show that Fe-Cr-Si alloy is composed of primary dendrite and interdendrite matrix, and the metal silicide Fe₃Si appears in the microstructure.The oxidation resistance of the Fe-Cr-Si alloy increased by more than 50 times at 900 ℃compared with that of 45 steel.Oxidation forms a composite oxide layer of Cr₂O₃ and SiO₂ to protect the substrate.The oxidation and diffusion of Cr in the early stage of oxidation is the main cause of the oxide film growth mechanism, while later it changes to be controlled by the oxidation and diffusion of Si due to the oxide film flaking.