Abstract: In order to improve the working environment of high concentration dust in underground, taking the 3^# coal seam of Sihe coal mine as the research object, based on the concept of dust source dust suppression and dust reduction, combined with laboratory measurement and field test, the characteristics of water injection, structural characteristics, the surrounding rock crack distribution of water injection hole, the flowing law of pulsating water injection, bedding and fissure, pores, and the effect of water injection and dust reduction are systematically considered and studied.The coal seam has the good characteristics of water injection, and the pores and cracks in coal are favorable for water injection and diversion.Due to the characteristics of original fissure and pulsation water injection, the fracturing fluid immerses into the coal body fissure in a certain order.The field water injection test proves that the effect of pulsating water injection is obviously better than one of the static pressure water injection, and the pulsating water injection can fully wet the coal body and the effect of dust reduction is better.