The corrosion characteristics and the degradation process of mechanical properties of concrete filled carbon fiber reinforced polymer（CFRP） steel tube pile foundations were studied by using the external direct current electrical source to accelerate corrosion under the simulated high humidity and thermal marine environment. The results show that due to the different influencing factors of each corrosion area of the pile foundation， the corrosion degree of the pile foundation is uneven. The corrosion is the most serious in dry and wet alternating area， followed by atmospheric area and the weakest in underwater area. CFRP material can prevent the intrusion of corrosive medium and limit the development of surface strain. The XRD patterns show that the main components of the corrosion products are Fe₂O₃， Fe₃O₄， α-FeOOH and γ-FeOOH， and the content decreases significantly with the application of CFRP. CFRP lateral restraint during the corrosion process can effectively improve the axial bearing capacity of the pile foundation. Through the analysis of the pile foundation strain， corrosion products and bearing capacity change law during the test， the degradation process of the pile foundation mechanical properties can be divided into three stages： general corrosion stage， moderate corrosion stage and severe corrosion stage.