In order to further improve the performance of Al2O3-SiC-C iron ditch castable,the iron ditch castable was prepared with super bauxite,brown corundum,SiC,Al2O3 micropowder,white corundum,silica micropowder,silica powder(SiO2>97%) and Si3N4 powder as main materials,and high alumina cement as binder.The effect of Si3N4 content on the performance of iron ditch castable was studied.The results show that the castable with Si3N4 has better mechanical properties,thermal shock resistance and oxidation resistance at high temperature.On the other hand,because of the β-sialon phase formed during the sintering process and tightly combined with corundum,the structure of the sample is compact and the slag resistance of the material is improved.