Abstract: Using 80%~90% tabular corundum and 10%~20% Al as the main material, a multiphase Al-AlN-Al₂O₃ material whose main crystalline phase is corundum and the bond phases are Al and AlN can be prepared by nitridation-sintering at 1 100 ℃ and surface oxidation treatment under 800 ℃. Made multiphase Al-AlN-Al₂O₃ of sliding gate of steel ladle, obtained excellent application effect. The experiments show that the slide plate is of compact structure because of the molten Al fill in the gaps of corundum grains and the bulk expansion with the formation of AlN and Al₂O₃. The Al-AlN-Al₂O₃ multiphase slide plate has excellent corrosion resistance and thermal shock resistance, so its service life is two times longer than that of Al₂O₃-C slide plate.