To construct an accurate 3D geological model of the grid engineering tower scene, we propose a method for 3D geological modelling of grid engineering towers on the basis of borehole data. The method generates a more accurate 3D geological model by improving the Delaunay triangulation algorithm and combining it with Kriging interpolation to process the borehole data. Furthermore, a detailed adjustment of the model is achieved through the introduction of geological profiles. The 3D geological model is constructed using the operational area of the power grid engineering survey as a case study, thereby accurately reflecting the geological conditions of the region. The results of testing demonstrate that the modelling method in this paper is more accurate than existing methods, and the generated 3D geological model not only provides a scientific foundation for tower placement and line design but also offers valuable insights for advancing the digital transformation of power grid engineering.