In order to study the influence of geometrical and mechanical parameters of structural surface on the safety and stability of rock slope, discrete element software 3DEC is used to carry out numerical simulation test. Taking safety factor as index and response surface analysis (RSM), the sensitivity of geometrical parameters (inclination, inclination) and mechanical parameters (normal stiffness (Kn), tangential stiffness (Ks), cohesion (c) and internal friction Angle (φ) of slope structural plane to slope stability has been studied. It is showed that geometrical parameters of the structural plane are the prerequisite for the stability of the slope. At the same time, the mechanical parameters of the structural plane will further affect the stability of the slope under the condition of collapse. In addition. the tangential stiffness of the sliding surface and the internal friction angle for the slope stability are highly sensitive to the slope stability, and the order of sensitivity is from large to small, tangential stiffness>internal friction angle>cohesion>method Directional stiffness. It is also found that the internal friction angle and tangential stiffness promote each other with the safety factors of the slope.