The invention relates to a double-adjusting device for feeding and supporting, comprising a base, a support seat and a lifting mechanism. The lifting mechanism includes a box body, a wedge block, a driver, a threaded rod, a support frame arranged in the box body and a transmission mechanism. The wedge-shaped block has a wedge-shaped surface, and the wedge-shaped surface is provided with a gap for the threaded rod to pass through. One end of the threaded rod is inserted into the base and driven to rotate by the driver, and the other end is screwed on the support seat after passing through the gap. The support seat has an inclined surface that fits with the wedge-shaped surface, and the wedge-shaped block fits between the base and the support seat. The support base is fixed on the top surface of the box body. The support frame includes two legs movably installed in a scissors shape, one end of one leg is placed on the conveyor belt of the conveying mechanism and is supported by a limit block fixed on the conveyor belt, and the conveyor belt is controlled by the motor of the conveying mechanism to move.