Screw conveyer with accurate metering function

The utility model relates to a screw conveyer capable of metering accurately, the lower part of the right side of a screw conveyer body is communicated with a discharging device, the discharging device comprises a left push plate, a right push plate and a box body capable of stretching up and down, and the box body comprises an outer box body and an inner box body; the inner wall of the outer box body and the outer wall of the inner box body are respectively provided with a plurality of first vertical raised lines and second vertical raised lines which are uniformly distributed along the peripheral walls, the first vertical raised lines are provided with vertical sliding grooves, the second vertical raised lines are correspondingly connected with the vertical sliding grooves in a sliding mode, and the upper ends and the lower ends of the vertical sliding grooves are provided with through holes penetrating through the outer box body. Fixed pins are arranged at the upper end and the lower end of the second vert