Abstract: In order to describe the tunnel's stress and deformation distribution by traditional mechanical model,the anisotropic elastic plastic model based on SMP was used,and through forming the dll file by programming with C++,the FLAC^3D secondary development of anisotropic elastic-plastic model was conducted.Results obtained from the simulation analysis indicate that the stress distribution of the tunnel anchors is asymmetric under the anisotropic condition.When the anchors in the plastic zone are lengthened,the plastic zone of the surrounding rock decreases obviously,and the stress distribution of the anchors becomes uniform.Through field application in Sichuan Road connecting line project of Jiaozhou Bay Tunnel,the key zone supporting method based on the anisotropic constitutive relationship proves to be available.