The Kondo insulator FeSi was prepared by DC magnetron sputtering and the effects of sputtering parameters on the formation of FeSi were investigated in detail. The formation of monosilicide FeSi was clarified using X-ray diffraction (XRD) and its microstructure was characterized by scanning electron microscopy (SEM). The results indicate that the sputtering gas pressure, the sputtering power and the Ar flux all have significantly effects on formation of FeSi and the crystalline of the film. The sputtering gas pressure has effects on sputtering yields, depositing rate and the energy of sputtering atoms, the sputtering power has effects on the kinetic energy and the diffusion ability of deposing atoms and the gas flux has the effects on the flowing state of Ar gas. The most optimal sputtering parameters for the preparation of the Kondo insulator FeSi by DC magnetron sputtering are given: 1.5 Pa for sputtering Ar pressure, 100 W for sputtering power and 20 SCCM for sputtering Ar flux.