Abstract: In order to provide safety guarantee for the transportation of low-concentration coalbed methane and realize the"co-extraction and sharing of coal and gas" in coal mines, the flame arrestor structure parameters designed for the low -concentration coalbed methane transportation safety guarantee system were optimized and the experimental test were carried out.The results indicate that the flame arrestor on the low concentration coalbed methane transportation pipeline is more preferred as a metal plate corrugated flame arrestor core with sufficient strength to resist strong explosion shock waves.In order to accelerate the cooling of the flame during propagation and reduce resistance, the flame arrestors is designed and processed into a structure of "coarse in the middle and thin at both ends", and the diameter of the middle flame arrestor core should be large enough; for the optimized DN500 dry flame arrestor, the number of corrugated plates is two, the spacing between corrugated plates is 30 mm, the thickness of the corrugated belt is 0.25 mm, and the diameter of the flame arrestor core shell is 1 500 mm. When the coal seam airflow speed is 15 m/s, the frictional resistance is 670 Pa. The flame arrestor is capable to resist the flame when the flame propagation speed is below 775 m/s.