Research conclusions：Results show that：(1)Beam size impacts on the embedded strengthening effect，especially on performance of the concrete beam after reinforcement under sustained load．(2)Deflection ratio is close to geometric similarity coefficient for scale model and prototype beams under the same load．(3)Under sustained loading，the concrete embedded CFRP sheets have good reinforcement effect，bearing capacity is improved less than the strengthened beam without initial load，and the improved value is nonlinear relationship with geometric similarity coefficient．Crack spacing of model beam is relatively larger after reinforcement，and it should be paid attention to in design．(4)The results can be references for the bridge reinforcement study and application．