The mechanism of creep movement of a landslide induced by cumulative gravitational load of colluvial from rockfall due to underground mining activity is presented in the study. The study area is located in an active coal mine in southwest China with seasonal precipitation. The analysis presented herein is based on field investigation and monitoring with numerical simulation using 3DEC discrete element method. The failure mechanism and deformation process of the landslide and the collapsed rock slope as well as the interaction between the landslide and the collapsed rock mass are centered in the study. The results show that the rockfall of the slope is attributed to the disturbance of underground mining, which caused a cumulative gravitational load imposed on the lower part of the slope, and in turn induced the creep movement and resulted in the landslide. Field monitoring data indicated a continuous creep deformation of the landslide and revealed the spatial and temporal relationship between the creep movement and the surcharge from displaced material of the rockfall. The rate of the creep movement also increased in the event of precipitation. The results signify the needs of continuous field monitoring and geohazard prevention measures in active mines, as the impact of slope instability comprised by the underground working at certain location can be far-reaching and induce geohazards at different spatial and temporal locations.