Subsea pipeline maintenance enhancing device and application method thereof

A subsea pipeline maintenance enhancing device, comprising a water storage tank (1), a control cabin (2) and an operation cabin (3) which are sequentially connected from top to bottom, wherein the control cabin (2) controls the water storage tank (1) to be filled with water or drain water to enable the maintenance enhancing device to be submerged or float upward, an outer wall of the control cabin (2) is provided with propellers (21) for controlling the maintenance enhancing device to move, the operation cabin (3) comprises a sealing zone (34) and an operation zone (35), the sealing zone (34) is located on an inner wall of the operation cabin (3), a pressure difference between an internal pressure and an external pressure is adjusted to enable the maintenance enhancing device to be separated from or absorbed on a subsea pipeline, and the operation zone (35) is located between the sealing zone (34) and the subsea pipeline (4);

• further comprising a maintenance mechanism, wherein the maintenance mechanism comprises a fiber placement wheel mechanism (22) and a steering wheel mechanism (23) which are arranged in the control cabin (2), a fiber placement head (26) arranged in the operation cabin (3) and a moving mechanism (33) connected to the fiber placement head, a fiber placement material that penetrates out of the fiber placement wheel mechanism is guided into the fiber placement head via the steering wheel mechanism, and the moving mechanism drives the fiber placement head to move transversely, longitudinally and/or circumferentially to carry out ply repairing.