Abstract: The deformation and revival of giant ancient landslide bodies pose one of the primary threats to the development of towns in the southwestern mountainous regions of China. Taking the ancient landslide in Daguan County of Yunnan Province as an example, this paper utilizes airborne lidar aerial survey, InSAR monitoring, multi-phase optical image comparative interpretation, and field investigation to study the development and evolution characteristics, as well as the stability status of the ancient landslide. Furthermore, it delves into the correlation mechanism between the evolution characteristics of the ancient landslide and the characteristics of urban spatial expansion. The results show that the ancient landslide in Daguan County exhibit obvious signs of staged movement evolution, and the existing landslide landform did not form in a single movement process. Overall, the ancient landslide is currently in a stable state, with some areas affected by human engineering activities or heavy rainfall, showing multiple signs of small and medium-sized local revival. Between 1970 and 2022, the urban area of Daguan County expanded by 7.56 times. Affected by urban spatial expansion, five new landslides and six resurgent secondary landslides on the surface of the ancient landslide are distributed near residential expansion areas and road excavation areas. The primary engineering factors influencing the stability of the ancient landslide in Daguan County are house-building, cutting slopes, and road excavation. In the process of urban construction and development in the western mountainous regions of China, close attention should be paid to the impact of human engineering activities on slope stability.