The suspension roasting of bauxite can not only effectively desulfurize, but it can also improve the dissolution properties of low-grade bauxite. Furthermore, it provides a good solution for the industrial utilization of low-grade bauxite with high sulfur and high silicon. In this study, suspension roasting was used to treat high-sulfur and high-silicon bauxite, and the effects of different roasting temperatures on sulfur content were investigated. The effects of roasting on phase transition and microstructure of bauxite were analyzed via XRD and SEM. At the same time, the effect of different calcination temperatures on the solubility of alumina was also studied via dissolution tests. The results showed that suspension roasting desulfurization was feasible. Indeed, the sulfur in bauxite was removed at 550, 600 and 650℃, and the sulfur content in bauxite was reduced to less than 0.2wt% when the suspension roasting temperature was 600℃ or above. As shown by the XRD spectrum, the kaolinite phase in the bauxite was decomposed to form amorphous metakaolin via roasting, and when the roasting temperature reached 600℃ or above, the kaolinite phase was found to be completely decomposed. Furthermore, SEM images indicate that, when the roasting temperature was 600℃, the dense structure of the ore particles was seriously damaged, resulting in grain refinement. On the other hand, local sintering occurred when the temperature reached 650℃. In addition, the diaspore crystal was destroyed by roasting, and the diaspore was activated. In particular, the crystal destruction was found to be most extensive under 600℃ roasting conditions. Thus, the effect of alumina dissolution under the same dissolution conditions was more pronounced than that of row ores and roasting ores at other temperatures. The optimum dissolution conditions were found to be: dissolution temperature of 270℃, caustic concentration of 245 g/L, lime addition of 14wt%, and dissolution rate of 96% or above, which met the requirements of industrial utilization.