The invention provides a module mechanism used for screw conveying. The module mechanism comprises a sliding table, wherein a motor is mounted at one end of the sliding table, and a first sliding plate and a second sliding plate which are connected with the sliding table into a whole are separately arranged at the two sides of the sliding table; a drag chain table is arranged at one side of the first sliding plate, and a drag chain is mounted on the drag chain table; an output shaft of the motor is connected with a driving wheel of the drag chain; a first sliding rail and a second sliding railare separately arranged on the upper surfaces of the first sliding plate and the second sliding plate in parallel; a moving plate is connected between the first sliding plate and the second sliding plate, the first end of the moving plate is connected to the first sliding rail, and the second end of the moving plate is connected to the second sliding rail; and the first end of the moving plate horizontally extends out of the connecting plate, and the connecting plate is connected with the drag chain. The module mechanism can reduce wear, and the cost is saved.