Through the finite element analysis software, fourteen strengthened beams are calculated in the condition of considering bonding-slip or not respectively. Comparing simulation results with test and theoretical calculation, We can draw the following conclusions: Testing reinforced concrete beams when there is no debonding, ANSYS simulation, theoretical calculations and experimental results agree well. Testing reinforced concrete beams when there is debonding. By considering the bond-slip calculation model calculation accuracy is higher. .Numerical results show that, prestressed CFRP with relative of prestressed girder of carbon fibre reinforced beam can significantly improve the cracking beam loading, and effectively improve the yield loads, but the ultimate load.