Abstract: According to the seam deposit conditions of the deep depth, low permeability and high ground stress in Huainan Mining Area, in order to solve the coal a nd gas outburst problems occurred during the cross-cut seam opening process, the hydraulic borehole flushing technology was tested in Xieqiao Mine and other five mi nes.With partial coal and gas released, the penetration improvement and the pressure releasing of the seam could have a rapid and safety seam opening.A special PZC K-C-* series nozzle was researched and developed for the hydraulic borehole flushing.The hydraulic borehole flushing technique and technical parameters was optimiz ed.A simulation comparison was conducted on the stress variations of the borehole surroundings before and after the borehole flushing.The experiment results showed that when coal quantity from the borehole flushing reached at 1.02 .5 t/m, the influence radius of the borehole flushing could be 5.59.0 m and the permeability coefficient of the seam would be increased by 70% to 370% .After the hydraulic borehole flushing conducted, the seam in the borehole flushing control zone would have a pressure releasing and a permeability increased.Thus the outburst potential energy and gas intrinsic energy would be released and the outburst danger of the cross-cut seam op ening face would be eliminated.