Abstract: In the view of low water component, low porosity, poor wettability and severe dust production characteristics of the No.2 coal seam in the Wang jialing coal mine, According to the coal seam drilling conditions , one-way long borehole water injection method decorated in the return air lane and the dynamic-static pressure water injection system were chosen to governance this hazard, and the technical parameters of coal seam water injection were determined Combined with the pre-injection test results. Then the investigation results show that the average water content of the coal can be increased by 1.04% after water injection, the total dust and respirable dust suppression efficiency can reached 36.7% and 31.5%.