The invention relates to a coal mine low concentration gas methane destroying method and a device thereof. The method comprises the following steps automatically carried out by the coal mine low concentration gas methane destroying device: (A) electrifying an oxidizing bed, and starting and heating the oxidizing bed to be at least 800 DEG C; (B) inputting coal mine low concentration gas methane into the oxidizing bed, carrying out the rapid reaction of methane and oxygen, and releasing heat; (C) storing the heat, and maintaining and continuing the reaction; (D) discharging clean waste gas out of the oxidizing bed after the reaction; (E) switching the direction, and inputting the coal mine low concentration gas methane into the oxidizing bed again so as to carry out an oxidization reaction and release heat; and (F) storing and outputting redundant reaction heat, and repeating the steps (B)(C)(D)(E)(F). The device comprises a switch valve mechanism, the oxidizing bed, a recovery valve mechanism, a gas inlet system and a process detection and control system. The switch valve mechanism and the oxidizing bed are assembled together and are integrated with the recovery mechanism and the gas inlet system into a whole. The method and the device are characterized by energy conservation, environmental protection, high efficiency, safety, and rapid and thorough reaction, and mainly applied to the coal mine low concentration gas methane destroying process project or similar projects.