Abstract: The effects of the liquid/solid ratio and reaction temperature of Bayer red mud and stirring speed on the absorption rate of sulfur dioxide and dealkalization rate of red mud were investigated, as well as the relationship between time and absorption rate of sulfur dioxide. The result showed that the optimal conditions on which the absorption rate of low-concentration SO2 is 93.14% are the liquid/solid ratio 5:1, stirring speed 150 r/min and reaction temperature 25°C, with the SO2 concentration in tail gas conforming to the National Discharge Standard. The absorption rate of SO2 decreases with prolonging time. Meanwhile, the dealkalization rate of red mud is 70.45%, i.e., the dealkalized red mud is available to be a raw material for cement production.