The invention provides a shape righting device used for an arc-shaped forge piece. The shape righting device comprises a base (1), carrier rollers (2), lower bases (3), first sliding blocks (4), second sliding blocks (6), upper bases (7) and a beam (8). The circle centers of the multiple carrier rollers (2) are located on a preset circle arc protruding upwards, and the multiple carrier rollers (2) on the base (1) are arranged in a transverse section; the first sliding blocks (4) are in sliding connection with the lower bases (3) located at the two ends of the base (1); the upper bases (7) are fixedly installed at the two ends of the beam (8) above the base (1), the second sliding blocks (6) are in sliding connection with the upper bases (7), and the binding faces of the second sliding blocks (6) and the first sliding blocks (4) are used for clamping the ends of the arc-shaped forge piece (5); when the beam (8) moves downwards, the second sliding blocks (6) are attached to the first sliding blocks (4) and move in the direction away from the base (1). By adopting the shape righting device used for the arc-shaped forge piece, people can better control to eliminate the deformation and stress of the arc-shaped forge piece, so that a good shape righting effect is achieved.