Screw conveyer of concrete mixing plant

The utility model relates to the technical field of concrete conveying equipment, and discloses a concrete mixing plant spiral conveyor which comprises a conveying pipe, supporting legs are fixedly connected to the outer surface of the conveying pipe, a waste box is arranged at the bottom of the conveying pipe, and universal wheels are arranged at the bottom of the waste box. The device has the following advantages and effects that when the waste box is moved to the position below the discharging opening and the interior of the conveying pipe is flushed, a worker starts the first air cylinder, the first air cylinder drives the first telescopic rod to extend downwards so as to drive the discharging plug to move downwards, and the top of the discharging plug is pulled out of the discharging opening; the sealing gasket improves the leakproofness between the discharging plug and the discharging opening, leakage during cement conveying is avoided, after the discharging plug is automatically pushed out of the disch