Abstract: In high-gas or coal and gas outburst coal mine, the gas drainage in roadway closed areas is an extremely important part of coal mine safety management. The traditional gas drainage method of unsealing confined has big hidden danger in the concentration control of gas drainage, and the domestic coal mining enterprises have repeatedly happened gas drainage accidents. Base on this, the technology of pressure air replacement gas drainage is proposed in the paper, which achieves the purpose of safe and fast gas drainage by putting it into practice.