Abstract: ‍ ‍In remote sensing， InSAR is a powerful technology for the generation of DEM with high accuracy and better resolution， permitting us to minitor the earth surface topography in all weather and at all times. Airborne InSAR system offers the advantages of variable track and multi-angle to collect InSAR data， enabling the efficient and precise acquisition of DEM. However， in areas with complex terrain， InSAR side-looking imaging tends to create extensive shadows and layover in steep terrain areas. These shadows and overlays manifest as information loss in SAR images， leading to invalid data in DEM. The invalid data severely impacts the quality and applicability of DEM data. To address this issue， this paper proposes a method for high-precision DEM generation of complex terrains based on airborne multi-angle InSAR. The task planning for multi-angle InSAR data acquisition that accounts for topography features is used to minimize invalid data caused by shadows and overlays. The high-precision InSAR data processing is used to ensure high consistency in DEM data accuracy from each angle. The rapid multi-angle DSM data fusion and filtering processing is used to achieve high-precision reconstruction of complex terrain DEMs under multi-angle InSAR configurations. Using the steep， discontinuous， and complex terrain of the western mountainous area of Sichuan Province as an example， this paper demonstrates the generation of high-precision DEM data through the fusion of InSAR data from three angles. The experimental result shows that the method proposed in this paper achieves DEM data with validity rate exceeding 99%.