The effects of the wet-dry cycles on the interface durability of the high strength concrete strengthened with prestressed CFRP (Carbon Fiber-Reinforced Polymer) were investigated by a four-point bending test.Three prestress levels,namely,0%,15% and 30% of the standard value tensile strength of the CFRP sheet,were im- posed in the test.Then,the interface degradation law was demonstrated by analyzing the influence of the wet-dry cycles and the prestress levels on the carrying capacity and the debonding failure model of specimens.The results reveal that the carrying capacity of the specimens decreases after 120 cycles,and higher prestress level causes the carrying capacity load to decrease faster,and that，with the increase of the wet-dry cycles,the failure model of the specimens transforms from the peeling of the protective layer of the concrete to the debonding of the resin layer.