In order to solve the problem of geological disaster management of slope landslide with dip weak layer in open-pit coal mine, taking the Zani River open-pit mine as the engineering background, based on analyzing the stability of the west slope, determination of anchor cable reinforcement position: Using dichotomy and residual thrust method, development of a calculation program for the axial force required for anchor cable reinforcement, The installation angle of anchor cable reinforcement is determined, parameters such as cable spacing are also determined: Finally, the reinforcement effect of west slope anchor cable is verified by numerical simulation. The results show that the anchor cable reinforcement position of the west slope of the Zani River open pit mine is determined as + 590 level, + 578 level, and + 566 level, determining that safety reserve coefficient 1.100 is satisfied, At this time the need for anchor cable force of 9700 kN, anchor installation angle of 30°, anchor spacing is 2 m, the row number of anchor cables is 15, discharge distance 4 m, length of anchorage section is 14 m. Landslide mode of west slope finally reaching boundary is a combined failure, landslide mechanism is traction type. The west slope after anchor cable reinforcement finally reaches the boundary slope, displacement and stress can be effectively controlled, reinforcement effect is remarkable.