Jaw backer assembly

The utility model provides a jaw backer assembly which comprises a jaw seat, a jaw plate arranged in a jaw of the jaw seat, two eccentric swing rods rotationally arranged in the jaw of the jaw seat through an eccentric swing rod positioning shaft, and an eccentric swing rod positioning seat arranged on the outer side face of the jaw seat and wrapping the eccentric swing rod positioning shaft. The two round holes are formed in the jaw plate, the inner hexagon screws are used for connecting the jaw seat and the jaw plate, the hexagon nuts are matched with the inner hexagon screws, the inner hexagon screws are arranged in the round holes, and the reset springs are arranged in the round holes through the inner hexagon screws. Due to the fact that the jaw backer assembly body is provided with the eccentric swing rod, the jaw plate is driven to move through the distance difference between the outer side wall of the eccentric swing rod and the eccentric swing rod positioning shaft, then the jaw plate is reset throug