Based on the differential element method, considering transfer of bond stress between corroded steel bar and concrete, and the compatibility of cross-section strain before and after bond stress transfer is considered, the deflection calculation model of corroded RC beams strengthened by steel plates and FRP is proposed in this paper. To validate it, the testing results in existing literatures and this study, are compared and analyzed. The results show that under different loading levels, compared with the strengthened beam without considering bond stress transfer, the deflection calculation results via proposed model considered the bond stress transfer of corroded RC beam strengthened by bending is more closer to the testing values. The relative errors of the former ultimate loading and the corresponding ultimate deflection is -0.6%~1.8% and -10.5%~9.1%, respectively, while the relative errors of the latter ultimate loading and the corresponding ultimate deflection is 1.1%~6.1% and -11.4%~-2.2%, respectively. The proposed model can also accurately predict the load-deflection curve of corroded RC beams strengthened by FRP materials (including CFRP and BFRP). The improved relative error of ultimate loading value is -3.6%~4.2%, and the that for ultimate deflection is -4.2%~8.3%.