With the development of modern long-span cable-stayed Bridges, the on-site cable-stayed cable of steel strand has been more and more favored by designers because of its advantages such as no need for large cable-making, transportation, hoisting and tension traction equipment, and superior overall protective performance of the cable. As a load-bearing component of cable-stayed bridge, the steel strand cable-stayed cable is called the life cable of cable-stayed bridge, and its reliability is one of the key factors to determine the safety and reliability of cable-stayed bridge. This paper mainly introduces the reliability research of cable anchoring system in the process of design and improvement of OVM250 steel strand cable system. Through the design means of effectively improving the fatigue performance of cable anchoring assembly, the optimal design of cable anchoring unit is carried out to ensure the safety and reliability of cable anchoring assembly. The fatigue test of OVM250-139 cable anchoring assembly is further conducted The excellent fatigue resistance of OVM250 steel strand cable system was verified.