In order to study the stability of high-fill slopes, based on the continuous-discontinuous coupling analysis theory, a boundary wall coupling method was used to establish a continuous-discontinuous coupling analysis model for high-fill slopes, and the strength reduction method was used to simplify rainfall conditions. Based on the actual landslide engineering cases, the soil parameters should be reduced by 15%, and the stability analysis of the high-fill slope under the influence of rainfall was carried out; by reducing the mesoscopic parameters, the safety factor of slope was obtained as 1.60. The possible deformation and failure of the slope under extreme conditions were analyzed. Through this case, the feasibility of the continuous-discontinuous coupling method for slope stability analysis was explored. The results show that the continuous-discontinuous coupling method can quickly, efficiently and intuitively evaluate the stability of high-fill slopes. The research conclusions can provide references for the application of continuous-discontinuous numerical simulation in geotechnical engineering.