Abstract: The evaluation of the ultimate tensile force is one of the most important problems for rock bolts and anchors.Rock,bond,bolt bar,and the cohesion among them influence the result.A numerical code,Rock Failure Process Analysis(RFPA),is developed and introduced.It simulates successfully the processes of some nonlinear and discontinuous mechanics problems in rock failure.Using the software,a series of numerical experiments are performed by orthogonal experimental method to check the influence of 6 main factors on the failure tensile load of the anchors.The results of numerical tests are compared with the results of physical tests and some conclusions are drawn.