Method for reinforcing and sealing coal mine and preventing gas

The invention relates to the technology of coal mine gas governance, in particular to a method for reinforcing and sealing coal mine and preventing gas. The method solves the problems of air leak and gas emission caused by cracks formed by disturbing coal petrology bed during coal mining in the prior art. The method comprises the following steps: modifying and reinforcing the support of neighbor sealing tunnels; drilling and grouting at the outer side of a sealing wall; and spraying polymer material at the surface of the sealing wall to reach a target for reinforcing the sealing wall and plugging the cracks of the wall. After reinforcing and plugging the sealing wall of the tunnel, softly cracked coal rock is cemented into one body, so that the whole intensity of wall rock in a whole sealing region is greatly improved, the average sectional shrinking ratio of the wall rock of the tunnel is less than 3%, the average air leak ratio of the sealing zone of the tunnel is reduced by more than 96%, and gas emission amount meets the requirement of the safety rules of the coal mine.