Air outlet dust falling device of heading machine and construction method

The invention discloses an air outlet and dust falling device of a heading machine and a construction method. The device comprises a supporting main body, a fog gun machine and a first water tank, the supporting body is arranged on the ground, the supporting body is of a prismoid structure and comprises a supporting frame and an isolation layer, the isolation layer covers the supporting frame, and the first water pool is arranged at the bottom of the supporting body; a first air inlet is formed in a first side surface of the supporting main body, a second air inlet is formed in a second side surface opposite to the first side surface, a fog gun machine is arranged at the first air inlet, and an air duct pipe is arranged at the second air inlet; according to the dust falling method, part of dust discharged by the air duct pipe is absorbed through the first water pool, the remaining dust discharged by the air duct pipe is absorbed through water mist discharged by the fog gun machine, the dust falling effect can