The National Astronomical Observatory of the Chinese Academy of Sciences used the Guizhou Karst Depression as the site to erect a 500m diameter spherical reflector in the depression, and built the world’s largest and most sensitive radio telescope, FAST. According to the requirements of this project, this paper developed a finished cable made of ultra-high fatigue performance steel strands that can withstand a stress amplitude of 500MPa. The test results show that this type of cable system has good static load performance and high fatigue life, greatly improving the reliability and durability of the steel strand cable system.