The early flexure failure model of the reinforced concrete beam strengthened with aramid fiber reinforced plastic(AFRP) was proposed.The failure mechanism was analyzed and the reasons that lead to this type of failure was provided.At the same time,based on the test results for flexural performance of reinforced concrete beam strengthened by externally bonding AFRP,the fit curve of the distribution of the strain of the fiber is obtained and the distribution of the interfacial bonding shear stress between the reinforced concrete beam and the fiber is analyzed.The factors that influent on the interfacial bonding shear stress are proposed.The measures that can help to avoid the early failure of the strengthened beam for the reality projects are also put forward.