Abstract: The failure of anti-dip slopes can induce serious geological disasters, so it is of great significance to study the stability and failure modes of anti-dip rock slopes with soft and hard interbed. This paper is based on numerical simulation method and uses discrete element software UDEC. Firstly, this paper takes into account the influence of the slope angle, rock inclination angle, slope height, total thickness of adjacent soft and hard rock layers, thickness ratio of hard and soft rock layers, ratio of mechanical parameter number of hard and soft rock layers, and the mechanical parameters of structural plane. Then based on orthogonal experimental design method, this paper designs 32 sets of orthogonal tests to simulate the stability of the slope and possible failure modes by the strength reduction method. The sensitivity analysis is conducted from two aspects of slope safety factor and displacement. It is found that the slope angle and rock inclination angle have a great impact on the safety factor, and the mechanical parameters of structural plane and slope height have a great impact on the slope displacement. Then the failure modes of anti-dip rock slope with soft and hard interbed are summarized and divided into three types: bending-dumping, collapse-sliding and block-dumping failures.The characteristics of each failure modes are analysed in detail.