The stabilization of slopes by placing passive piles is one of the innovative slope reinforcement techniques in recent years. There are numerous empirical and numerical methods for designing stabilizing piles. They can generally be classified into two different types: (1) pressure/displacement-based methods; (2) finite element/finite difference methods. However, seldom studies have been done on the stratified rock slope reinforced by piles, so in the present paper, the numerical simulation software FLAC3D is adopted to model the stratified rock slope, then the reinforced effect like deformation and stress of slope are studied, showing that if the pile is driven at the mid-bottom place of slope surface, the effect of controlling deformation of rock mass is the best. With increase of the length of pile, the maximum displacement of slope is decreased gradually.