Abstract: Underground bifurcation roadway is more common, underground roadway inhibition of explosion isolation technology can effectively contain the further expansion of gas explosion disaster. According to the characteristic of the flame staying longer at the bifurcation, the new technology of negative pressure chamber explosion suppression with the dual role of negative pressure diversion and wire mesh quenching is proposed, and using Ansys Fluent 19.0 software, numerical simulation analysis is used for the T-pipe gas explosion flame propagation characteristics under the condition of the external negative pressure chamber, and comparative analysis is carried out for the non-suppression chamber, external negative pressure chamber and the negative pressure chamber with the external filler. The results show that: when the flame passes through the bifurcation of the pipe, part of the high-temperature flame is sucked into the interior of the cavity by the effect of negative pressure cavity in the form of vortex replacement, and the rest of the high-temperature flame flows to the straight pipe through the bifurcation to continue the combustion reaction; the external negative pressure cavity can effectively attenuate the shock wave pressure in the T-pipe and reduce the chemical reaction rate, and the negative pressure cavity filled with wire mesh is more effective than the negative pressure cavity alone in exploding the flame in the T-pipe. Under the dual action of negative pressure drainage and quenching of wire mesh, when the explosive flame passes through the wire mesh, the flame will be reflected and scattered many times, and the collision rate between the free radicals involved in the gas explosion chain reaction and the pore surface of the wire mesh will increase, the number of free radical losses will increase, the flame combustion reaction strength will be weakened and the impact pressure will be reduced.