The bond degradation and the degradation mechanism induced by corrosion-induced crack were investigated numerically using 3D RBSM. The numerical method that considered both corrosion expansion and shear stress transfer behavior from rebar by interface elements was developed. Validation of the proposed model showed the reasonable results of the bond performance of non-corroded specimen and the bond degradation due to rebar corrosion. Moreover, the bond degradation mechanism was investigated through the crack development and stress distribution for different rebar positions. It was found that the bond degradation is related to reduction of surrounding concrete constraint of rebar due to corrosion-induced crack and the degraded bond strength can be evaluated by the surface crack width of corrosion-induced crack.