Abstract: A landslide in a certain open-pit mine in the Democratic Republic of the Congo was se ⁃ lected as the object of the study.The research systemically analyzed the causes and mechanisms of the landslide on the open-pit slope，and based on the limit equilibrium analysis method and 2D finite element analysis method，the stability of the existing landslide body was evaluated.At the same time，a comprehen⁃ sive treatment plan of "slope cutting and load reduction +interception drainage +anti-seepage"was pro ⁃ posed and implemented on-site for treatment.The research results show that the slope collapse is the result of the combined action of multiple disaster-causing factors，mainly including geological structure fragmen ⁃ tation，weak rock quality，and rainfall-induced seepage，etc.The overall slope failure process presents a composite failure mode of local collapse -traction-type sliding -push-type sliding.Local collapse of the lower step triggers traction-type landslide failure of the upper step，and the accumulated landslide body generated by the collapse exerts a large thrust on the lower platform，causing push-type landslide failure of the lower platform，thereby leading to the occurrence of landslide disasters.Based on the numerical simula⁃ tion results of Slide and Phase，before the treatment，the safety factor of the slope was close to the critical state，and there was potential instability，urgently requiring slope treatment.The "slope cutting and load reduction +interception drainage +anti-seepage"comprehensive treatment plan was adopted to conduct construction treatment on the eastern landslide body.After long-term observation during the rainy and dry seasons，the stability of the treated slope was good，indicating that the treatment plan was truly effective. The research results can provide scientific basis and engineering reference value for the treatment of open pit mine landslide disasters in the Democratic Republic of the Congo and similar geological conditions.

Key words: fractured structuralbelt, open-pit mine, landslide mechanism, stability, treatment scheme