Abstract: Based on the water jet slotting coal seam permeability increase technology, the stress distribution state of the coal after slotting is analyzed, and the radial and tangential stresses of the slotted borehole are calculated. Based on the theoretical analysis of the influence radius of the water jet slotting, the technical process based on the water jet slotting drilling arrangement is determined. According to the field measured data, the statistical dynamic indicators were analyzed to verify the effect of coal seam gas extraction after water jet slotting. The research shows that compared with the conventional drilling, the gas extraction concentration with water jet slotting drilling is increased by 3.6 times, the flow is increased by 2.7 times, the pure flow is increased by 9.7 times, the average wind discharge of the west wing of the upper third mining is decreased by 0.68 m³/min and reduced by 26.98%. The gas content of the water jet slotting drilling section is more reduced by 0.48 m³/t; when the extraction radius is 3.0　m, the extraction time of the water jet slotting drilling section is 41days. The comparison was shortened by 43　days.