China is the main importer and consumer of manganese with low grade of manganese ore, high smelting consumption and single treatment process. In order to improve the grade of manganese ore, reduce the fuel consumption of manganese smelting and its production cost, the process system of drying, preheating and roasting manganese ore is studied by orthogonal test method, the process characteristics and difficulties of roasting are analyzed, and the effects of the roasting temperature and the partial pressure of O₂ and CO₂ on the decomposition reaction of MnCO₃ are studied to finally find out its reasonable roasting technology. The results show that, when the particle size of manganese ore is 15 ~ 40 mm, the drying temperature is 400 ℃, the drying time is 3.0 min, the preheating temperature (temperature ≤ 550 ℃), the time is 3.0 min; roasting IR (temperature is 900 ℃, the time is 10 min), the roasting temperature is 1100 ℃, the roasting time is 10 min, the soaking temperature is 950 ℃, and the soaking time is 6 min, the roasting effect of manganese ore is the best, the TMn mass fraction in manganese ore is increased from 21.34% to 32.32%, the carbon removal rate is 98.94%, and the burn-off rate is 28.40%.