In this paper, the fatigue crack growth behavior along the interface between carbon fiber reinforced polymer (CFRP) sheets and concrete induced by intermediate flexural crack in CFRP-sheet strengthened concrete beams was studied, both experimentally and theoretically. The fatigue crack growth behavior of the intermediate crack-induced debonding was investigated by modified beam tests. The major variables considered in the test were loading amplitude, concrete strength, and the width ratio of CFRP-sheet to concrete. Test results indicated that three stages were observed in the evolution of CFRP-concrete interfacial crack propagation under cyclic loading, including debonding initiation, steady propagation, and instability propagation. Furthermore, the fatigue crack propagation rate grew with the increase of the load level, concrete strength, or the width ratio of CFRP-sheet to concrete, and was reduced as load cycles increased in the steady propagation stage due to the interfacial friction existed in the debonding zone. Based on the test results and fracture mechanic method, a crack growth prediction model, which considered the effects of concrete strength and width ratio of CFRP-sheet to concrete, was proposed for predicting the whole crack growth process and fatigue life of intermediate crack-induced debonding of CFRP-concrete interface under cyclic loading. The predicting results using this proposed model agreed well with test results.