Ventilation device used under mine

The ventilation device comprises a shell and an electric push rod fixedly installed in the shell, a lifting plate is fixedly installed at the extending end of the electric push rod, and a recycling mechanism used for collecting dust is movably arranged on one side of the electric push rod. A filtering mechanism for filtering dust is arranged on the other side of the electric push rod; the output end of an air outlet pipe is communicated with an exhaust pipe, the input end of an air suction pipe is communicated with the input end of a dust suction pipe, the output end of the air suction pipe is blocked by a turnover plate, at the moment, a piston is separated from the dust suction pipe, the dust suction pipe sucks air into the air suction pipe, and dust accumulated on a dustproof net is sucked into a recycling box; the extending end of the electric push rod is reset to the longest state again, due to the action of the thrust spring, the piston blocks the dust suction pipe again, and the situation that dust flo