Abstract:At present, a certain gold mine adopts open-pit mining for production, which has formed a slope with a height of about 400m. The western slope and other areas have been affected by multiple intersecting faults and have experienced instability and sliding, seriously threatening the safety of mining production. As the mining depth continues to increase, the stability of the slope further decreases, and there is an urgent need to conduct research on the stability and support methods of the slope. On the basis of relevant indoor experiments, this article uses numerical simulation methods to establish a three-dimensional model of the mining area. From the perspectives of stress, displacement, and shear strain increment, the stability of the study area during the expansion process to the final boundary is analyzed, and corresponding reinforcement schemes are proposed. The results show that as excavation continues, the open-pit slope gradually enters an unstable state due to the influence of faults, self weight ground+groundwater+earthquake, and ultimately becomes unstable; When prestressed anchor cables with anchoring section length of 12m, free section length of 25m, 36m, and 37m, inclination angle of 20 °, and spacing of 4m are used in the fault area for reinforcement, the slope can remain stable. The research results provide theoretical basis for mine design and production.