Abstract: The experimental study on flexural capacity of strengthened RC beams about C13,which were detached from the damaged building of Wenchuan earthquake was carried out,then loading to the same damage. There were 22 RC test beams adopting 8 kinds of strengthened methods by composite CFRP sheets under monotonic loading,it was investigated strength,stiffness,ductility,crack and strain changes of the beams. Results showed that: 1) The ultimate bearing capacity of reinforcement compound solutions of automatic glue pouring,replacement concrete after picked slot,implanting steels and pasting CFRP was much higher than direct pasting CFRP; cracking load and ductility was improved evidently. 2) The maximum stress of CFRP on which reinforcement compound solutions was bigger than direct pasting,the high-strength effect of CFRP was used very well,interoperability between new and old concrete was strong,which could play a good role in high-strength CFRP. 3) For the beam strengthened with the compound technology,raising the amount of CFRP could further improve the stress of steel, and effectively improve the cracking load and limit load of beam.