Abstract: In order to study the mechanical behavior and crack development of low strength reinforced concrete beams under different reinforcement methods, a three-dimensional finite element model of reinforced concrete beams is established by finite element software. By comparing with the experimental data, the simulation results are in good agreement with the experimental results, which accurately reflect the stress characteristics and stress process of concrete beams, and verify the rationality of the numerical model. Through the simulation analysis, it is further concluded that compared with the u-shaped hoop of carbon anchorage beam, the steel u-shaped hoop anchorage can restrain the debonding of CFRP sheet and concrete, thus improving the reinforcement effect.