Abstract: The same slope displacement causes different tensions among steel strands considering its different lengths. Especially the shorter one, when the slope displacement is close to its limited value, has a higher probability of abruption. The solution to this problem can consider the prestressing of steel strand. Proper pretension value is derived based on mechanical characteristics and practical experience in order to equalize the tension of every steel strand when the slope displacement reaches its allowable value, which makes the anchor work best.