The utility model discloses a straightening machine, which comprises a machine frame, two bracket mechanisms and at least a group of straightening mechanisms, wherein the two bracket mechanisms are respectively arranged on the left and the right sides of the machine frame, and are used to bear a shaft to be straightened, the straightening mechanisms comprise two rotating arms, a straightening telescopic cylinder and two straightening dies, the two rotating arms are symmetrically arranged on the front and the rear sides of the machine frame, and are respectively articulated with the machine frame. A cylinder tube end and a cylinder rod end of the straightening telescopic cylinder are respectively articulated with the two rotating arms, thereby being convenient for the operation of the straightening telescopic cylinder to drive the rotating arms to swing corresponding to the machine frame. The two straightening dies are respectively arranged on the two rotating arms, and the inner surfaces of the straightening dies are inner concave arc surfaces which are matched with the shaft to be straightened. When the straightening telescopic cylinder extends out, the two straightening dies arerespectively resisted with the shaft to be strengthened, and apply straightening force. When the straightening telescopic cylinder retracts, the two straightening dies are respectively separated fromthe shaft to be straightened. The straightening machine effectively controls the straightening precision through self structure of equipment, and has the characteristics of simple and reliable operation.