Chuck

The utility model discloses a chuck which comprises a chuck body, and a clamping hole penetrating through the chuck body is formed in the chuck body. The clamping hole comprises a connecting hole and a seed crystal hole which are oppositely arranged, the connecting hole and the seed crystal hole are coaxial, the connecting hole is used for being connected with a lifting structure of the single crystal furnace, and the seed crystal hole is used for clamping a seed crystal; the seed crystal hole sequentially comprises a first section, a first connecting section, a second section, a second connecting section and a third section in the direction from the connecting hole to the seed crystal hole, the first section is located on the side, close to the connecting hole, of the first connecting section, the third section is located on the side, away from the connecting hole, of the second connecting section, and the surfaces of the first connecting section and the second connecting section are cambered surfaces or inc