Abstract: Using a combination of finite element simulation and experimentation, the impact of reinforcement layer material quantity, properties of reinforcement materials, and characteristic parameters of reinforced concrete (RC) beams on the flexural performance of RC beams strengthened with high-strength steel wire mesh/engineered cementitious composites (ECC) was investigated. Firstly, the finite element (FE) analysis model of existing nondestructive RC beams strengthened with high-strength steel wire mesh/ECC was established, and its effectiveness and accuracy were verified by comparing with the experimental results. The validated FE model was adopted to analyze the influencing factors of flexural performance of strengthened beams systematically. The results indicate that the strengthening method can significantly enhance the flexural bearing capacity, stiffness, and ductility of RC beams, with improvement ranges of 7.81% to 61.84%, 6.35% to 40.90%, and 5.92% to 50.16%, respectively. With the increase of longitudinal steel strand reinforcement ratio, thickness and cracking stress of ECC, the promotion range of bearing capacity increases, while the increase of longitudinal steel reinforcement ratio and section height of RC beams decrease the increment of bearing capacity. The increase of the thickness of ECC and the reinforcement ratio of longitudinal steel strand increase the promotion range of stiffness, but the promotion range decreases with the increment of longitudinal reinforcement ratio, concrete strength and section height of RC beams. The increment of ductility only increases with the increase of concrete strength. On this basis, combined with relevant mechanical theories, the calculation formula for the limit amount of steel strands for flexural strengthening and simplified calculation formulas for the normal-section bearing capacity of RC beams reinforced by high-strength steel wire strand mesh-reinforced ECC are proposed, calculation results are in good agreement with experimental and numerical simulation results.