Abstract: Automatic powder explosion suppression device is one of the important safety equipment for the low concentration gas pipeline．We research automatic powder anti-explosive device for transporting the inhibitory effect of pipeline in the low concentration of gas explosion propagation with 500 mm explosion pipe, and the explosion suppression mechanism were analyzed．Results show that the automatic powder explosion suppression device suppression effect is greatly affected by the mounting position; the minimum installation distance between flame sensor and explosion suppression is 20 m．The explosion flame behind the explosion suppression device must spread a certain distance and can be completely extinguished, there is a range and time of the process．Shock pressure peak due to the inhibitory effect of producing a gas-injection pressure off and ABC ultrafine powder extinguishing agent is attenuated, but the decay rate is relatively small.