The invention provides an anti-overturning reinforcement system for single-column pier bridges, which comprises a steel structure support, a steel connecting base, and rigid tie rods; the steel structure support comprises two semicircular hoops with cantilevers, and the surface, which is in contact with a pier, of each semicircular hoop is provided with reserved holes for the mounting of anchor bolts at intervals; the external surfaces of the semicircular hoops are provided with axial reinforcing ribs; the two semicircular hoops are connected through first high-strength bolts to hoop both sides of the pier, and the semicircular hoops and the cantilevers are of an integrated structure; one end, which is far from the hoop, of each cantilever is provided with a vertically through mounting through hole; the steel connecting base is fixed on the bottom of a bridge, the center of the steel connecting base and the center of the through hole are on the same vertical line, and both ends of eachrigid tie rod are respectively fixedly connected to the steel structure support and the steel connecting base. The invention can effectively enhance the anti-overturning performance of a single-column pier bridge, the structure is simple, stress is clear, construction is convenient, the anti-overturning reinforcement system has relatively good economical efficiency and appearance, and the invention is suitable for popularization and application in the field of bridge reinforcement.