Abstract: Low permeability coal seam gas drainage is the bottleneck of China's coal mine gas control. In recent years, water jet technology has been greatly developed in rock cross-cut coal uncovering and the elimination of ground stress. Therefore, carrying out water jet technology to strengthen the coal seam gas drainage is important. Using hydraulic jet to expand the direct influence range of drilling, through the investigating of volume, surface area, single-hole gas extraction amount and drilling affect radius of disturbance coal, the datum of the hydro-jet technology and drilling extraction technology are compared and analyzed. The paper achieves that the borehole diameter increases 11.7 to 19.2 times, the volume of the disturbance coal increases 3 471 to 6 971 times; The borehole gas decay cycle extends 7 to 10 times, the single hole drainage effect increases from 6 to 8 times.