Structural plane is different from common crack, as it is often under pressure and has non-linear normal and tangential deformation behavior. This paper simulates the propagation of non-linear deformation structural plane by 3D displacement discontinuity method (DDM). Through least square regression of the elements near the tip, the stress intensity factor (SIF) of the tip is obtained. Maximum energy release rate criterion is adopted to be the fracture criterion in this paper, assuming the propagation occurred in the normal plane of the front edge, KI is modified to consider the effect of mode Ⅲ crack. The structural plane model is considered as a hyperbolic non-linear model, the Barton-Bandis model is adopted as the normal deformation model, the Kulhaway model is adopted as the tangential deformation model, and the Mohr-Coulomb criterion is adopted as the shear strength criterion. The result shows that the propagation direction is along the direction of the load, DDM could efficiently trace this process.