The invention relates to a transverse reinforcement structure for a concrete bridge. According to the transverse reinforcement structure, a reinforcement beam is transversely arranged between every two adjacent bridge bodies or inside each bridge body, and each reinforcement beam is of an I-shaped structure or an X-shaped structure and connected and fixed to the corresponding bridge body through a connecting piece. The appearance of the reinforced bridge is not damaged in the reinforcement process of the reinforced bridge, the construction technique is simple, the construction working period is short, economic performance is good, the self weight of each steel cross beam is small, thus the small self weight of the bridge is increased, construction can be conducted under the premise that traffic is not affected, and good social benefits are achieved. After reinforcement is completed, bridge integrity can be increased, transverse distribution of loads of the T-shaped beams and box-shaped beams can be effectively improved, the problem that a single beam bears force is solved, the transverse rigidity of the double-column-type concrete bridge is increased, and the steel cross beams are convenient to operate and maintain and can be detached and replaced, so that the transverse reinforcement structure has wide application prospects in the field of transverse reinforcement for the concrete bridges