The invention belongs to the technical field of rerailing equipment and particularly relates to a hydraulic rerailer. The hydraulic rerailer comprises a transverse moving bridge, a transverse moving oil cylinder, a first oil cylinder, a second oil cylinder and a jack. The transverse moving bridge is provided with a base. Both the first oil cylinder and the second oil cylinder are located on the upper end face of the base. A cylinder body of the first oil cylinder and a cylinder body of the second oil cylinder are hinged to the base. A piston rod of the first oil cylinder and a piston rod of the second oil cylinder are both hinged to the jack and used for making the jack ascend or descend. A piston rod of the transverse moving oil cylinder is used for making the base move in the length direction of the transverse moving bridge. By the adoption of the hydraulic rerailer provided by the invention, a derailed car can be safely and stably jacked and moved transversely, fast on-site installation is facilitated, and the rescue efficiency is improved.