In order to improve the performance of Al2O3-SiC-C castables for iron trough, samples were prepared using brown corundum, dense corundum, activated alumina micropowder, ball pitch, and silicon as main raw materials, calcium aluminate cement as the binder. Several kinds of silica fumes (93SiO2, 96SiO2, and 99SiO2) with different particle size distributions and chemical composition were added to research the effects on the properties of castables. The results show that the sample with 99SiO2 fume has high water requirement for molding, but the bulk density is the lowest, the apparent porosity is the highest, the oxidation resistance is the worst, and the permanent linear change on heating is low after firing at 1 450 ℃ for 3 h. The bulk density and the apparent porosity of the sample with 93SiO2 fume or 96SiO2 fume are equivalent, the hot modulus of rupture of the sample with 93SiO2 fume is the lowest, and the slag resistance of the sample with 96SiO2 fume is the best. The comprehensive performance of the sample with 96SiO2 fume is the best.