The invention relates to a feeding clamping double-lifting device which comprises a base, a supporting seat and a lifting mechanism. The lifting mechanism comprises a box body, a supporting frame, a conveying mechanism, wedge-shaped blocks, a driver and threaded rods. Notches are formed in wedge-shaped faces of the wedge-shaped blocks. One end of each threaded rod is inserted into the base in a penetrating mode and driven by the driver to rotate, and the other end of each threaded rod penetrates through the corresponding notch and then is screwed on the supporting seat. The supporting seat is provided with oblique faces matched with the wedge-shaped faces. The wedge-shaped blocks are arranged between the base and the supporting seat in a matched mode. The supporting seat is fixed to the top face of the box body and driven by the lifting mechanism to ascend and descend. The supporting frame comprises two supporting legs which are movably installed in a crossed mode. One ends of the two supporting legs are movably installed on the bottom face of the box body and a conveying belt of the conveying mechanism correspondingly, and the ends which are arranged on the conveying belt abuts against a limiting block fixed to the conveying belt. The conveying belt is controlled by a motor of the conveying mechanism to move. The supporting seat is positioned above the top face of the box body through cylindrical rods. The distance between the supporting seat and the base is adjusted by rotating wrenches of buckles.