<p>This paper presents a case study of a deformed rock mass (DRM) exhibiting toppling and sliding characteristics. To clarify the intrinsic mechanisms underlying the distinct deformation patterns observed in different parts of the DRM, an integrated approach combining remote sensing and numerical modeling was applied. Unmanned Aerial Vehicle (UAV) photogrammetry was used to obtain a high-accuracy three-dimensional digital surface model. Geological interpretation and GIS-based analysis were performed to characterize rock mass structures across the DRM. Kinematic analysis was conducted to preliminarily identify the most probable failure mode and key discontinuity sets controlling deformation. The dynamic response of the slope was simulated using Universal Distinct Element Code (UDEC) and interpreted together with macroscopic field observations to assess the potential role of seismic shaking in DRM formation. Based on the spatial variability of slope geomorphology and rock mass structure, the DRM is subdivided into three regions (i.e., the toppling-sliding zone, the crushed zone, and the disturbed zone). Tractional groove and reverse scarps are identified on the slope shoulder, reflecting pronounced tensile-shear deformation governed by pre-existing discontinuities, while compressional features are mainly observed in slope middle and front sections. Kinematic, geological, GIS-based, and UDEC analyses collectively indicate that spatial variability in rock mass structure exerts a major control on the toppling-sliding of the DRM. Moreover, topographic amplification may have enhanced the seismic response and facilitated DRM development together with other long-term geological process.</p>