To investigate the improvement effect of carbon fiber reinforced polymer (CFRP) reinforcement technology on the performance of cantilever beams, a numerical model of the cantilever beam was established using ABAQUS finite element analysis software. The effects of CFRP reinforcement method, CFRP reinforcement rate, and CFRP prestress on the bending performance of cantilever reinforced beams were analyzed. And based on numerical simulation, some specimens were selected for on-site testing to analyze their loading process, failure mode, load deflection curve, and steel bar strain, in order to verify the accuracy of the finite element model. The results show that the finite element model is in good agreement with the experimental results, and can effectively predict the ultimate load, deflection, and damage mode of the reinforced beam; The CFRP reinforcement method, CFRP reinforcement rate, and CFRP prestressing all have a significant impact on the bearing capacity of cantilever reinforced beams. In addition, The feasibility of applying surface embedded prestressed CFRP reinforcement technology to cantilever beams was verified through finite element and experimental research.