Abstract: Disclosed are a pre-tightening force repairing method, a repairing method involving a combination of a pre-tightening force and a clamp, and a repaired pipeline. The repairing method includes: (a) fixing part of a fiber material to a pipeline; (b) applying a pre-tightening force to the fiber material, winding multiple layers of the fiber material around the pipeline under the pre-tightening force; (c) in the state of applying the pre-tightening force, completing the curing of the multi-layer fiber composite material; and (d) mounting a clamp outside a repairing part of the fiber composite material. The magnitude of the pre-tightening force is designed to overcome the situation whereby a fiber composite material layer comes unstuck from the pipeline due to the radial shrinkage of the pipeline caused by a decrease in internal pressure and/or the axial stretching of the pipeline after the pipeline, which is under pressure, is repaired.