Bauxite ores usually contain some iron and titanium oxides, which are difficult to remove simultaneously with conventional beneficiation processes. The oxides of iron and titanium will form low melting point phases during the preparation of mullite by sintering with bauxite, resulting in a reduction of the high-temperature properties of mullite. This review represented the solid solution behavior of iron oxides and titanium oxides in mullite based on the open spatial structure of mullite and its ability to accommodate different metal ions at different temperatures and atmospheres. The solubility of TiO2 in mullite is 1.36%-4.10% at 1 400-1 700 ℃. Fe2O3 of 10%-12% can make a solid solution in mullite microstructure at 1 300 ℃. Ti3+ and Fe2+ are poorly solidified in mullite. Moreover, the formation of solid solutions of iron and titanium with mullite provides a limited enhancement of mullite properties. In addition, the efficient use of mullite containing iron and titanium was also discussed.