Nano-barium ferrite (BaFe12O19) with its excellent magnetic properties (high uniaxial anisotropy, high Curie temperature (723K), large saturation magnetization (theoretical value 71. 6Am2/kg) and high distortion Coercive force (theoretical value 67000e, etc.) and corrosion resistance, oxidation resistance and wear resistance are widely used in various aspects of the national economy.