Abstract: Againsted the double hidden danger of spontaneous combustion and upper corner gas gauge in a super thick seam coal of Shan xi ,which was created by adjacent mining goaf respiration caused by mining process and simple gas drainage and poisonous gas leakaged, combined with occurrence and physical characteristics of goaf gas, proposed regional stereo replacement technology of surface hole drainage and nitrogen injection,.The practice results showed that the average concentration of gas and carbon monoxide in goaf reduced from 6% to 0.8%，reduced by 86%, reduced from 16ppm to 6ppm，reduced by 62%,with an obvious control effect,provided safety guarantee for production of small coal pillar and spontaneous combustion working face in extra thick coal seam.