Abstract: Weak interlayers are key factors affecting the stability of open-pit coal mine slopes. To effectively address the technical challenges of landslide geohazard prevention, control, early warning and forecasting, and to ensure safe and efficient open-pit mining, the full-process evolutionary characteristics of slope instability with weak interlayers need to be investigated. On the basis of an optimized mesoscopic parameter model for rock discrete elements, a finite difference-discrete element coupled method is used to analyze the evolutionary characteristics of failure paths in slopes with weak interlayers, investigate the dynamic response characteristics of multivariate state parameters at different locations, reveal the temporal correlation characteristics among multivariate state parameters, and establish quantitative relationship models among sliding distance, sliding speed, and landslide body geometric characteristics. The results show that the effective modulus E*, the ratio of normal to shear stiffness K* and the parallel cohesion c′ have significant effects on the elastic modulus E, Poisson's ratio μ and compressive strength σ_c respectively; In rotational landslide, the multivariate status parameters response time of deep monitoring points is generally earlier than that of surface monitoring points. In the sitting landslide mode, the closer the horizontal distance between the monitoring point and the sliding surface, the earlier its multivariate status parameter response time; the multivariate parameter response time of the same monitoring point is: acoustic emission event number N_AE, stress σ, velocity v, kinetic energy E_k, displacement x and gravitational potential energy E_p; the sliding distance s is positively correlated with the slope angle α, the slope height H, and the weak interlayer inclination angle β. The sliding speed v_s is negatively correlated with the slope angle α and the weak interlayer inclination angle β, and is positively correlated with the slope height H.