With the advancement of smart water conservancy construction, high slopes in hydraulic and hydropower engineering face issues such as delayed information feedback, insufficient on-site monitoring, and inadequate construction quality control. A digital solution was proposed that integrates BIM (building information modeling), finite element analysis, and MR (mixed reality) technology to address these challenges. Using MicroStation software, a BIM model was created based on drilling data, which is then imported into ABAQUS for three-dimensional geostress balance and two-dimensional slope rainfall infiltration analysis. By deploying an on-site monitoring system and making secondary development, the analysis results and monitoring data are fed back into MicroStation, achieving interoperability between numerical calculations and the BIM environment. Furthermore, the BIM model is imported into the Unity3D platform, with the help of the HoloLens2 MR headset, virtual three-dimensional models, analysis results, and monitoring data are overlaid onto the real environment, enabling visual and interactive analysis at the engineering site. The practical application of this technology is showcased in this paper through the Maiwan Hydraulic Hub Project, demonstrating its effectiveness in raising the digital management level and improving the safety assurance capabilities of high slopes in hydraulic and hydropower engineering. The integration of these technologies not only optimizes and collaborates information models in actual projects but also provides new support and solutions for the safety, reliability, and efficiency of engineering.