Abstract: The terrain of open-pit mines is complex，the height difference is significant，and the tradi⁃ tional surveying and mapping method is low in efficiency and insufficient in accuracy，which is difficult to meet the needs of rapid monitoring of geological disasters such as road collapse，restricting the accurate im⁃ plementation of mine ecological restoration. In order to solve this problem，the innovative application of UAV oblique photogrammetry in mine ecological restoration was studied with the objective of monitoring road collapse in open-pit mines，aiming to solve the difficult problems such as low efficiency of surface in⁃ formation acquisition and insufficient accuracy of collapse recognition in complex terrain. By optimizing UAV aerial survey parameters，high-resolution multi-view image data of mining area was collected，radial and tangential distortion correction models were adopted to improve the geometric accuracy of the image， and disturbance such as vegetation and noise was eliminated based on the filtering algorithm of Triangulation Irregular Network (TIN)，and high-precision three-dimensional mine surface model was constructed to real⁃ ize automatic identification and quantitative analysis of subsidence areas. The results show that the plane er⁃ ror and elevation error of the 3D model generated by this method are less than 0.015 m and less than 0.02 m， and the recognition accuracy of collapse boundary is 98.7%. The monitoring results are completely consis⁃ tent with the field survey. Compared with the traditional RTK measurement，the efficiency is increased by more than 5 times，and the small deformation can be captured，which provides an efficient and low-cost technical means for mine geological disaster monitoring，and significantly improves the collapse warning ability. The high-precision three-dimensional model can support the fine design of ecological restoration projects，and the technical process can be extended to other open pit mining areas. The research provides re⁃ liable data support and reference for mine ecological restoration，helps the intelligent transformation of mine environmental governance，and has important engineering application value.

Key words: UAV oblique photogrammetry, open-pit mine, road collapse, ecological restoration