The invention belongs to the technical field of machining, and discloses a self-centering chuck jaw. The self-centering chuck jaw is composed of a rotary plate and an elastic synchronous rotary shaft.The elastic synchronous rotary shaft and the rotary plate are connected through a butterfly hinge. In work, a chuck can automatically adjust the position of a workpiece, so that the center of the workpiece overlaps with the center of the chuck. The self-centering chuck jaw has the beneficial effects that the structure is simple, the functionality is high, the stability is good, the cost is low, and the clamping time is shortened; and errors caused by dislocation of the workpieces are reduced, and thus, the work efficiency is improved.