At present, circular steel wire and S-shaped wire are mainly used for protection winding of bridge main cables. Compared with the circular steel wire, the S-shaped steel wire has obvious advantages:The main cable will be deformed(expansion/contraction) by force , and the coating layer on the outside of circular steel wire will crack, however S-shaped steel wire as main cable winding, after winding, they press and buckle each other as a whole, the outer coating is smooth, no cracks, the main cable protection effect is good, which can effectively block the invasion of rainwater and sea fog condensate water, reduce the corrosion of other media to the main cable of suspension bridge, and improve the service life of the main cable of suspension bridge. It is the development direction of the main cable winding protection of suspension bridge.