Abstract: The uplift-restricted and slip-permitted (URSP) continuous composite beam refers to a continuous composite beam that is equipped with URSP connectors in its negative bending moment zone. The application of URSP technology can effectively alleviate the cracking issues in the concrete slab of the negative bending moment region, and it has been widely used in bridge structures. Bridges are frequently subjected to dynamic loadings from vehicles, and the fatigue of them is a key concern in this study. Thusly, the performance evolution of continuous composite beams with URSP connectors during fatigue action is investigated by fatigue experiment. The post-fatigue performance changes are analyzed in detail from four aspects, including concrete slab cracking, deformation and stiffness, interface slip and internal force redistribution. The experimental results verify that there is no significant difference in fatigue performance evolution between URSP composite beams and ordinary composite beams. The experiment finds that characteristics such as crack width and internal force redistribution of the composite beams change little before and after fatigue, but deformation gradually increases with loading cycles. Fatigue-induced deformation growth can reach up to 20%, which is not negligible. Therefore, the fatigue deformation of composite beams is further investigated. The composition and causes of fatigue deformation of composite beams are explained from the mechanism level, and design and calculation methods for fatigue deflection applicable to general composite beams are proposed. A comparison with existing fatigue test data demonstrates that the fatigue deformation calculation method proposed is simple to operate and, produces reliable results.