The eastern margin of the Qinghai-Tibet Plateau is a high-risk area for global debris flow activities, influenced by active tectonic movements, steep terrain, and heavy rainfall. Using aerial imagery and field surveys, 3,643 debris flow gullies were identified in the study area. Due to high-dimensional data and nonlinear processes, a factor analysis-Gaussian mixture model was employed to reduce dimensionality and perform cluster analysis on 15 indicators, including stratigraphy, earthquake, terrain, rainfall, temperature, and vegetation. This analysis identified debris flow disaster-prone units in the area, and GeoDetector was used to determine the main controlling factors for debris flow activities. The study area was divided into 11 disaster-prone units, with seven showing frequent debris flow occurrences. Based on the two maximum determinant powers calculated by GeoDetector, these seven units were grouped into four debris flow control zones. Zone I, located in the middle and lower reaches of the Yalong River Basin (units 1, 5, and 9), accounts for 39 % of the area with debris flows mainly influenced by tectonic and climatic factors. Zone II (units 2 and 10) located in the control zones of the Longmenshan, Minjiang, and Huya Faults, is dominated by tectonic activity. The longitudinal gradient of debris flow gullies (200 parts per thousand-350 parts per thousand) in this area is steepest, with the highest probability of debris flow occurrence. Zone III (unit 3) in the upper Yalong River Basin, experiences debris flows primarily controlled by rainfall, with minimal topographic relief. Zone IV, located in the upper Dadu River Basin, is influenced by both topography and tectonic activity, with the youngest geomorphological evolution stage (0.53 < HI < 0.6). This study provides a comprehensive understanding of debris flows by examining the distribution, characteristics, and controlling factors of disaster-prone environments in complex mountainous regions.