Waste gas purification device for environmental protection engineering

The utility model discloses an environmental protection engineering waste gas purification device which comprises a main body unit, the main body unit comprises a purification box and a gas outlet pipe, the gas outlet pipe is installed at the top of the purification box and communicated with the purification box, a fan is installed at the top of the purification box, a gas inlet pipe and an exhaust pipe are installed on the fan, and the gas inlet pipe is communicated with an engineering waste gas pipeline; a gas guide pipe is arranged at the bottom of the purification box, a gas conveying pipe is arranged on the gas guide pipe, the purification unit comprises a gas collecting pipe arranged in the purification box, and the end, extending into the purification box, of the gas guide pipe is fixed and communicated with the gas collecting pipe. After the activated carbon particles are replaced, a threaded cylinder is rotated to move downwards, so that the threaded cylinder abuts against a second sealing ring, the