Abstract: As a new type of high performance composite material, high-strength steel wire strand (HSWS) meshes reinforced engineered cementitious composites (ECC), which makes full use of the excellent mechanical properties of HSWS meshes and ECC, has the advantages of ultra-high ductility and toughness, excellent crack-control ability and high strength. In order to explore the effect of secondary load on the flexural behavior of reinforced concrete (RC) beam strengthened with this new composite material, the bending test of RC beams strengthened with HSWS meshes reinforced ECC was conducted, considering the effects of strengthening in load-carrying state, damage degree of the original beam, and reinforcement ratio of longitudinal HSWS. The influence mechanism of secondary load on the flexural performance of strengthened RC beams was analyzed, and the influence laws of these factors on the flexural behavior of RC beams strengthened with HSWS meshes reinforced ECC in load-carrying state were explored. The results show that the flexural capacity, stiffness, ductility and toughness of RC beams strengthened with high-strength steel wire meshes reinforced ECC in load-carrying state are increased by 38%-65%, 20%-81%, 0%-18% and 33%-116%, respectively, and the crack development of RC beam can be well restrained, and the crack width can be reduced. Compared with the RC beams strengthened in unloading state, the beams strengthened in load-carrying state exhibit obvious strain hysteresis in the reinforcement layer, resulting in the worse constraint effect on the crack of the original beam, and its flexural capacity, stiffness and toughness decrease, but its ductility is improved. The flexural capacity, stiffness, ductility and toughness of the beams strengthened in load-carrying state decrease as the original beam damage degree increases, but grow as the reinforcement ratio of HSWS increases properly.