Dust falling device for civil engineering

The dust falling device comprises a placing base, supporting rods are welded to the four corners of the top of the placing base, a top base is welded to the top ends of the supporting rods, an oil cylinder is fixedly installed on the top of the top base, the bottom end of a piston rod of the oil cylinder penetrates through the top base to be welded with a vertical rod, and an elastic mechanism is arranged on the side wall of the vertical rod. The top of the placing seat is connected with the top seat through the supporting rod, the oil cylinder is arranged on the top seat, the vertical rod is installed at the bottom end of the piston rod of the oil cylinder, the bottom end of the vertical rod penetrates through the transverse plate to be provided with the motor seat, and the motor seat is provided with the motor. A motor is installed at the bottom of the motor base, a cutting blade on the motor is located in a blocking cover, an adaptive sealing piece is arranged at the top of the motor base, when a wood plat