Preparation of bauxite-based sintered mullite homogenized grog was introduced and its application in ladle castable was studied. Two kinds of bauxite-based sintered mullite homogenized grogs were used, named as GA and GB, respectively. The results show that bauxite-based sintered homogenized grog with uniform components, stable microstructure and mullite as main crystal phase can be prepared using joint process of three-step homogenization, automatic component batching, wet co-grinding, high-temperature calcinations. It also indicates that carbon steel ladle castables with GA or composite aggregate of GA and GB as main materials have the same excellent general performance indicators, great erosion resistance, anti-strip performance and longer service life in field applications, and compared with castables with single aggregate of GA, the castables with aggregate of GA and GB as main materials had higher cost performance because of lower bulk density of GB.