Abstract: Gas extraction plays an important role in coal mine gas control, among which gas extraction sealing technology is the key. This technology plays a decisive role in the concentration, effectiveness, and gas utilization of gas extraction. The most widely used sealing method in China is the polyurethane polymer foam material sealing method, but due to the serious problem of air leakage, it is difficult to achieve the ideal sealing effect. The Du'erping mine combines the widely used sealing method in China with cutting-edge methods in other countries, using the "bag type grouting sealing method" as the gas extraction sealing method. After testing and comparing with the main sealing method in China, the "polyurethane sealing method", this newly introduced method has significantly improved the sealing effect.