The deterioration of structural performance caused by steel bar corrosion has become a great threat to the safety of reinforced concrete (RC) structures and the development of the economy. Strengthening of deteriorated RC structures using externally bonded (EB) FRP systems is an economical and efficient method for improving the safety and reliability of the structures. However, it brings new problems: steel corrosion and concrete deterioration have great effects on the bond stress transfer properties among the concrete, reinforcement and FRP. This proposed project will thus carry out an experimental study and numerical simulation on the shear performance of corroded RC beams strengthened with EB FRP, focusing on the coupling effects of steel corrosion and the three major shear failure modes, i.e., the failures with diagonal compression, shear compression and diagonal tension. The proposal will reveal the effect of corrosion-induced concrete cover cracking on the FRP bond stress transfer properties, and illustrate the collaborative working principles among the FRP, concrete and reinforced in the state of steel corrosion. A finite element model will be established to analyze the shear enhance mechanism of the corroded RC beam strengthened with EB FRP and finally to develop the shear strength model. The expected achievements of this project can have a great contribution to the promotion and development of the design theory of RC structures shear-strengthened with EB-FRP and can provide a technical support to the shear strengthening of deteriorated RC structures with EB FRP.