Due to structural defects and improper corrosion protection measures in traditional suspension bridge main cable systems, almost all suspension bridge main cable systems worldwide have varying degrees of corrosion in their main cable steel wires. This paper proposes for the first time to change the original open main cable structure to a closed main cable structure, and apply the mature OTC (Oxidative Polymerization Coating Corrosion Protection Technology) and PTC (Multilayer Mineral Grease Coating Corrosion Protection Technology) technologies of the National Marine Corrosion Protection Technology Engineering Research Center of the Institute of Oceanology, Chinese Academy of Sciences, to effectively block the corrosion pathways of suspension bridge main cable systems, improve the corrosion protection performance of suspension bridge main cable systems, and reduce the technical difficulty of maintaining suspension bridge main cable systems, thus meeting the design life requirements of suspension bridge main cable systems.