Abstract: In order to guide a correct design and application of water sealing fire barriering and explosion venting device applied to the mine gas transport pipeline, gas explosion test pipeline system with two different diameters of DN500、DN700 were applied to the experiment study on the pressure and flame spreading law of diff erent density gas explosion, and the fire barriering and explosion venting performances.The results showed that an installation location and the effective water sealing height would be the key factor affected to the fire barriering and explosion performances.The air velocity in water sealing tank determined the water sealing height and r esistance lost of the device.In order to ensure the fire barriering and explosion venting performances, a reliable water level monitoring and control system should be ins talled on the device.The gas flow area of the water sealing tank of device with pipe diameter below DN500 should be four times larger than the gas flow area of the gas transport pipeline.During the application, the installation location of the device should have a distance not over 30 m to the explosion location and the gas velocity in th e gas transport pipeline should be controlled not over 10 m/s.