To address the anchor challenges of CFRP tendons used as cables, this study investigates the fatigue performance of a bonded CFRP tendon anchor system employing a three-segment anchorage design. Fatigue tests were conducted under a maximum stress of 0.5 \(f_{u}\) and stress ranges between 500 and 800 MPa. The fatigue failure mechanism was analyzed based on the bond–slip behavior between the CFRP tendon and the bonding medium. The effects of cyclic loading on tendon and sleeve stress, bond stress evolution in the anchor zone, and tendon stiffness were also evaluated. The results indicate that the anchor system withstood 2 million cycles under a 500 MPa stress range at 0.5 \(f_{u}\) maximum stress. Fatigue life was influenced by the stress range, with failure modes shifting from tendon splitting to tendon slippage as the stress range increases. Tendon axial strain progressively decreased and then stabilized with loading cycles, accompanied by a 22% increase in axial stiffness after 2 million cycles. The steel sleeve exhibited a slight increase in axial strain under cyclic loading, though the associated stress levels and amplitudes remained low. Within the anchor zone, bond stress and its amplitude were highest near the loading end, and bond stress within the tensioning end anchorage exceeded that in the fixed end. Fatigue failure initiated at the bonded interface near the loading end and propagated toward the free end, ultimately leading to global tendon slippage. Based on the fitted S–N curve, a stress range below 365 MPa is recommended for the three-segment anchor system with a fatigue lifespan exceeding 100 million cycles.
