Abstract: Natural manganese ore were used as catalyst to study the low-temperature selective catalytic reduction and denitrification process of manganese ore. The effects of different conditions such as manganese ore grade, reaction temperature and NH₃/NO ratio on the low temperature selective catalytic reduction and denitrification process of manganese ore were investigated by using simulated flue gas.At the same time, a series of characterization methods were used to analyze the physical and chemical properties of manganese ore. The results show that low-grade manganese ore has good denitrification effect in denitrification process.Under the conditions of temperature of 250℃, 5% O₂, NH₃/NO=1.0, the NO removal rate of C^# low-grade manganese ore reaches 98%. The concentration of NO in the denitration tail gas is less than 12.27 mg/m³.The denitrification active material uniformly distributed inside the manganese ore, the stable crystal structure, the loose porous internal structure, and the rich hydroxyl groups provided by the manganese ore structure water and the surface adsorbed water promote the circulation of the denitration reaction.