In comparison with conventional anti-sliding pile,anti-sliding rail pile have certain advantage,but now little research has been conducted on anti-sliding rail pile,especially in its anchorage depth.Taking an engineering example,this paper discusses the optimal anchorage depth of anti-sliding rail pile based on rigid landside mass limit equilibrium,and the optimal anchorage depth is calculated using PLAIXS program,the given optimal anchorage depth is 2.2 m shorter than designed one,so the project cost can be reduced.