The invention relates to a bending chuck device of a thin-wall metal tube, and is used for carrying out stretch bending forming on the thin-wall metal pipe. The bending chuck device comprises a clamping sleeve, a tension plate and a traction device, wherein a plurality of holes are circumferentially formed in the side wall of the clamping sleeve, and a plurality of protrusions are arranged on theouter side of the tension plate in the circumferential direction, the protrusions are matched with the holes, and the size of the hole is arranged larger than the size of the protrusion; a traction device is arranged on the side of the bottom of the tension plate to ensured that the tension plate 4 can be inclined in the bending forming process. According to the bending chuck device of a thin-wallmetal tube, the structural design is ingenious, the bending chuck device can be used in a stretch bending forming process, and different forces can be applied to different parts of the metal tube, the stress distribution of the deformation of the thin-wall metal pipe is effectively improved, and the risks that inner side wrinkling and the outer side pulling crack is reduced.