<p>A large amount of high-iron red mud is produced during the treatment of high-iron gibbsite ore by the Bayer process, and the iron in the red mud is difficult to separate and recover efficiently. To solve the problems of efficient separation and recovery of iron and aluminum from high-iron bauxite and resource utilization of red mud, a new process of high-temperature calcification-biomass transformation-magnetic separation was proposed in this study. Through the synergistic effect of high-temperature calcification-biomass hydrothermal reduction, the dissolution of aluminum minerals and the reduction transformation of iron minerals are realized simultaneously. Under the optimum reaction conditions, the actual dissolution rate of Al₂O₃ was 88.4%. The iron-rich phase in bauxite is mainly converted into magnetite, the reduction rate is 98%, and the <i>ω</i>(Na₂O) in red mud is reduced to 0.25 wt.%. The magnetite phase is recovered by wet magnetic separation. Multi-stage magnetic separation can improve the recovery rate of iron concentrate. The first-stage magnetic separation intensity is 1200 Gs, and the second-stage magnetic separation intensity is 2400 Gs. The grade of iron concentrate can be increased to 41.97%, and the recovery rate of iron concentrate is 65.89%.</p>