The sodium bicarbonate (NaHCO3) superfine powder was grinded by using LNI-180A impact mill. NaHCO3 powder particle size, specific surface area, power consumption and the characteristics of morphology were discussed under different classifier speed. The results showed that with the classifier speed decreased from 1 050 r/min to 540 r/min, the superfine powder size decreased from d90=45.630 μm to 13.090 μm, the specific surface area turned from 0.86 m2/g to 1.83 m2/g, the yield was reduced to 65%, whereas energy consumption was decreased by 2.6 times. Combined with particle size and energy consumption, the optimal classifier speed of LNI-180A impact mill is 750 r/min for sodium bicarbonate powder, in this parameter, the output size d90 is 24.950 μm, specific surface area is 0.94 m2/g, unit power consumption is 70.66 kW•h/t. The grinded NaHCO3 powders were taken lamellar or porous structure, the particles sizes and distributions are uniform, which has favorable dispersibility, and better using as a fire extinguishing and desulfurization material.