Abstract: The effects of the dust reduction by spraying of op emulsifier are investigated using the self-designed dust reduction by spraying experimental equipment. The results show that the dust reduction efficiency of adding OP emulsifier is 22.9% higher than that of water for the mine dust with the particle diameter less than 75μm,and the effects of the dust reduction are very great for the different concentration mine dust. Research result are reference for perfecting the dust reduction by spraying working in the coal mine.