Dehumidification method for main cable of suspension bridge

The invention discloses a dehumidification method for a main cable of a suspension bridge. The surface of the main cable is sealed and wrapped by the wrapping tape, and the wrapping tape and the internal main cable steel wires form cavities at the top and the bottom, thereby facilitating the flowing of dry gas. The principle that moisture in the main cable circularly rises and falls day and nightis ingeniously utilized, and when the moisture is gathered in the cavity, dry gas is introduced to discharge the moisture. Dry gas flow resistance is small, required operation time is short, energy consumption is low, an air feeder does not need to be installed on the upper portion of the bridge tower, and investment is saved; moreover, dry gas can flow at low pressure, the wrapping tape is not easy to break, a special gas inlet cable clamp, a special gas outlet cable clamp and a corresponding pipeline system are not required to be mounted, high-altitude operation in system maintenance is reduced, and the maintenance