Abstract: The geological structure information of high-steep rocky slopes in open-pit coal mines constitutes a core element for mine disaster risk identification and slope stability analysis. In view of the problems existing in traditional geological structure investigation and analysis, such as incomplete structural information, low collection efficiency, and inaccessible operation areas, the current relevant work is difficult to fully reveal the complex geological structural characteristics inside the slope. To address these issues, this study takes the high-steep rocky slope of Liubao Open-pit Coal Mine in Inner Mongolia as the research object and establishes an integrated analysis framework that combines comprehensive geological structure detection, non-contact rock mass parameter acquisition, slope stability calculation, and failure mode analysis. The framework is designed to achieve refined identification and quantitative evaluation of stability risks for high-steep rocky slopes under open-pit mining conditions. First, drilling and high-density electrical resistivity tomography (ERT) methods were combined to infer the internal geological structure characteristics of the slope, including lithological assemblages, fracture structures, and goaf distributions. Second, unmanned aerial vehicle (UAV) photogrammetry and the window sampling method were applied to interpret and count joint and fracture parameters; based on the geological strength index (GSI) and the Hoek-Brown strength criterion, rock mass parameters for different lithological zones were derived. Finally, slope stability assessment and failure mechanism analysis were carried out, revealing two typical instability evolution modes of the west slope in Liubao Open-pit Coal Mine: one is the tensile failure mechanism controlled by joint-fracture propagation, and the other is the through-sliding mechanism induced by goaf disturbance. Meanwhile, FLAC^3D numerical simulation method was employed to verify the potential development processes of these two typical failure modes. This study realizes the analysis of internal geological structures and instability mechanisms of high-steep slopes under poor geological conditions, providing reliable technical support for geological structure information acquisition and stability evaluation of slopes in open-pit coal mines.