Nano-hematite with multi-porous texture was prepared from the transformation of limonite by thermal treatment. The prepared nano-hematite was utilized to remove Mn²⁺ from aqueous solution. The effect of heat treatment temperature, initial pH, Mn²⁺ concentration and contact time on removal of Mn²⁺ was investigated. The results of characterizations (XRD, TEM, BET) showed that the hematite exhibited the smallest pore size of 2.7 nm and the largest surface area of 107.4 m²/g after thermal treatment at 300℃. The results of batch experiments indicated that the effect of pH varying from 5 to 10 on the removal of Mn²⁺ was marginal and could almost be ignored. The maximum adsorption capacity of the thermally treated limonite to Mn²⁺ reached 6.45 mg/g. The kinetics results showed that the adsorption of Mn²⁺ by nano-hematite followed pseudo second-order kinetic model. The prepared nano-hematite presented excellent adsorption performance and catalytic oxidation to Mn²⁺. Furthermore, the existence of manganese oxide promoted the adsorption performance and dramatically improved the role of catalytic oxidation in removal of Mn²⁺ from aqueous solution.