The pretress loss of anchor cable is the key cause induced the anchor structure failure; based on investigating all influencing factors
a method for calculating prestress loss is put forward; the influencing factors of prestress loss of anchor cable under long-term loading are analyzed; the relaxation model of steel strand
rheological model of rock as well as creep damage model of grouted material are put forward respectively; and using these theory to predict the prestress loss of anchor cable. There are the significant- sense to design and manage anchor cables.