The invention discloses a fixator for a dual-layer corrugated carton. The fixator comprises an outer plate-shaped piece, an inner plate-shaped piece and a supporting rod. A round through hole is formed in the middle portion of the outer plate-shaped piece. An internal thread is arranged on the inner wall of the round through hole. The middle portion of the inner plate-shaped piece and one end of the supporting rod are fixedly connected into an integrated structure. The supporting rod is cylindrical. An external thread is arranged on the outer side of the supporting rod. The external thread located on the outer side of the supporting rod is rotationally connected with the internal thread located on the inner wall of the round through hole. Handles are arranged on the surface of the outer side of the outer plate-shaped piece. The handles are symmetric with the round through hole as the center axis. According to the fixator for the corrugated carton, through rotational connection betweenthe outer plate-shaped piece and the supporting rod, the distance between the inner plate-shaped piece and the outer plate-shaped piece can be adjusted at any time, operation is convenient, the structure is simple, the manufacturing cost is low, and wide-range popularization is facilitated.