## 1 Introduction
Although the discontinuum methods (UDEC, DDA, NMM) represented by the discrete element method (DEM) can directly reflect the primary fracture of rock mass and simulate the crack expansion between blocks, there are still some problems in dealing with the deformation and fracture of internal parts of the slope under external forces [21; 22; 23; 24]. Therefore, it is urgent to develop a new simulation method that can not only analyze the dynamic stability of the slope under seismic load but also describe the entire dynamic failure process of cracking, expansion, penetration, detachment, sliding (rolling), collision and deposition of the landslide-anchorage structure system. The combined finite-discrete element method (FDEM), designed by [PERSON] (2004), builds a bridge between the continuum and discontinuum methods, which is an excellent method to deal with continuous-discontinuous problems and is very suitable for the study of the issue of the dynamic evolution process of the landslide-anchorage structural system under seismic load [25; 26]. The dynamic equation of the entire FDEM system is solved in the same way as that of DEM, that is, according to [PERSON]'s second law, at the beginning of each step, the second-order difference method is used to solve the motion equation to obtain the velocity and displacement of nodes and update the coordinates of nodes. Based on the test data, a mathematical model of the structural plane considering the vibration deterioration effect is established and implemented in FDEM. Subsequently, the characterization of the anchor cable element is achieved based on the FDEM source code, and the calculation model of the dynamic process of the anchorage structure system is established. It is worth emphasizing that this study focuses on earthquake-induced landslides, thus ignoring the influence of other factors such as primary fissures, groundwater, and porosity. Finally, the following established model is homogeneous and isotropic. This paper studies the evolution mechanism of the landslide-anchorage structure system according to the FDEM model, which helps to understand the entire failure process of earthquake-induced landslide fundamentally and provides a powerful technical guarantee for the control design of landslide and the effectiveness and long-term stable operation of the landslide-anchorage structure system, which is of great significance to the theory and engineering practice. Section 1 introduces the superiority of FDEM and its application in landslide disasters. In order to simulate the entire dynamic evolution process of the landslide-anchorage structural system under seismic load, Sections 2 and 3 improve the source code of FDEM. Section 2 mainly considers the vibration deterioration effect of the structural plane and Section 3 establishes the combined one-dimensional and entity element model of anchor cable. Section 4 reproduces the dynamic evolution of the landslide-anchorage structural system under seismic load, aiming to demonstrate that the improved FDEM is capable of analyzing the dynamic evolution mechanism and simulating the entire process of destabilization and damage of the landslide-anchorage structural system. Conclusions are given in Section 5.