Abstract: Permeability enhancement by hydraulic jet cavity gas pre-drainage to prevent regional outburst has been tested, The test site is selected in the 150112 air return way heading face of Shanxi Lu'an Group Yiyuan coal mine which is a outburst mine. The process of forward hydraulic jet cavity was adopted in the test. 5 hydraulic jet cavity drilling with length of 120m were hit on the heading face, and 52 cavity were jet. The size of the cavity is a cylinder of 1m×?0.8m, the water pressure of the cavity making is 16-18MPa, and total amount of slag is 150t. Through this test, the results are as follows: boreholes，the hydraulic jet cavity can increase the average gas extraction amount from 62m3/d to 316m3/d. In the process of tunneling, the gas concentration of heading face return air is reduced from 0.7% to 0.4%. The water content in coal seam of jet cavity area is higher than that in the not jet cavity area, pulverized coal is reduced, the amount of dust in the process of tunneling is reduced, the number of gas dynamics is reduced, and the efficiency of tunneling is greatly improved. However, the process of hydraulic jet cavity will cause certain damage to the coal seam structure and roof and floor, during the tunneling, we need to strengthen the support management of the two sides of the roof and roadway. Moreover, the technology of hydraulic jet cavity is not suitable for mines with soft rock in the top and bottom of the roadway.