Explosion-proof underground flue

The utility model discloses an explosion-proof underground flue which comprises a flue body, the flue body comprises a first transverse section, a first vertical section, a second transverse section and a second vertical section which are connected in sequence, and a combustible gas detector, an infrared detector and a nitrogen release device are arranged on the first transverse section; the nitrogen release device comprises a nitrogen container and a nitrogen pipeline, an electromagnetic valve is arranged on the nitrogen pipeline, a nitrogen release port is formed in the first transverse section, and the nitrogen pipeline is communicated with the nitrogen release port; an explosion venting pipeline and an explosion venting sheet are arranged on the first vertical section, and a one-way explosion-proof valve is arranged on the second transverse section; a control system is also arranged; combustible gas in the underground flue can be detected; according to the explosion-proof device for the underground flue,