Based on the differential element method thought, 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 established in this paper. In order to verify the correctness of calculation model in this paper, the test results in existing literatures and authors’, are compared and analyzed. The results show that under different load level, compared with the strengthened beam without considering bond stress transfer, the deflection calculation results of model considered the bond stress transfer of corroded RC beam strengthened by bending is more close to the result tested values. The error range of former ultimate load and corresponding ultimate deflection is -0.6%-1.8% and -10.5-9.1%, respectively, while the error range of latter ultimate load and the corresponding ultimate deflection is 1.1%-6.1% and -11.4%- 2.2%, respectively. The model in this paper can also accurately predict the load-deflection curve of corroded RC beams strengthened by FRP materials (including CFRP and BFRP). The error range of ultimate load value is -3.6%-4.2%, and the error range of ultimate deflection is -4.2%-8.3%.