In order to solve the problem of the decrease of flexural capacity of reinforced concrete (RC) beams

this paper proposes a new approach of steel plateCFRP composite reinforcement: the steel plates are anchored at the bottom of the reinforced concrete beam

and carbon fiber reinforced polymer (CFRP) sheets are pasted on the steel plates after having been prestressed. The calculation formula for normal section flexural capacity of the composite reinforcement beam in balancedreinforced failure is derived

and the results got by the calculation formula are compared with the test results in relevant literature. The results show that theoretical value is close to test value of relevant literature

the failure modes of beams in the test are consistent with predicted failure modes. Compared with the prestressed CFRP sheet reinforcement

the values of ultimate moment of RC beams strengthened with prestressed CFRP sheets and steel plates increase 37.4%~57.1%

the values of yield moment increase 60.4%~95.7%; Compared with the steel plate reinforcement

the values of ultimate moment increase 25.4%~39.7%. It shows that steel plate-CFRP combination reinforcement technology improves flexural behavior of RC beams effectively.