The invention belongs to the technical field of civil engineering. A flexural reinforcing structure for a concrete beam is arranged in a beam body of the concrete beam, and comprises a first caulkinggroove, second caulking grooves and anchors fixedly arranged in the second caulking grooves, wherein the first caulking groove is formed in one side face of the beam body; the second caulking groovesare formed in the first caulking groove at an interval; a reinforcing strip is cooperatively embedded in the first caulking groove; the reinforcing strip is cooperatively and fixedly clamped between the anchors, and the reinforcing strip is supported in the caulking groove of the beam body through the anchors. The invention also discloses a flexural reinforcing method for the concrete beam. The flexural reinforcing structure and method for the concrete beam have the advantages that the structural design is reasonable, the stability is good, the durability and operability of the product can begreatly improved, the reinforcement effect is optimized, and the bearing capacity of the reinforced concrete beam is improved.