Abstract: The integrated slope is divided based on structure fracture to form the anti-dip and quasi-lamellar structures.This paper takes the slope behind the power house of a cascade hydropower station as an example, and uses a 2D discrete element and 3D finite difference methods to stimulate the deformation characteristics and the failure evolvement of the quasi-lamellar rock slope. The results show that the deformation and damage process of this kind of slope mainly experiences three periods: (1) an initial stage，in which the major deformation is shear dislocation between blocks and shear creep of local gently inclined joint; (2) the metaphase of damage process, in which the speed of rock mass dumping is accelerated, the sliding of the front slope is promoted, and the toppling-steps and cracking on the slope surface form; (3) a later stage, in which the shear deformation spreads toward the interior of the slope, the plastic zone is connected with each other, and gradually traces the gently inclined joints or the interface of weathering to form sliding zones which are characterized by “ladder-like distribution” in the space form. Finally, conditions for deep creeping are created.