Improving the design efficiency of hydropower hub buildings and promoting the application of intelligence in engineering construction and operation management have been critical issues in hydropower engineering construction. The major challenges are mainly reflected in the difficulties of multidisciplinary collaboration and the inefficient coordination of work involving multiple parties. This paper proposes a building information modeling (BIM)-based technology system architecture for digital design, intelligent construction, and intelligent operation, which combines BIM technology with geographic information system (GIS), computer aided engineering (CAE), internet of things (IoT), artificial intelligence (AI), and other technologies. The proposed system includes a BIM-based multi-professional forward collaborative design method, a BIM-based engineering construction management model, and a real-time safety analysis and evaluation technology system based on actual measured safety information and construction. The hydroelectrical engineering BIM (HydroBIM) comprehensive control platform is developed. In the planning and design stage, the platform enables the whole process and full-professional collaborative digital design. In the engineering construction management stage, it supports the whole process and all-round information management and control of contract, schedule, quality, safety, and investment. In the operation management stage, the platform facilitates the integrated management of engineering safety evaluation, early warning, and emergency plan based on monitoring data and the consistency criterion of positive and negative evaluation. The application of this technology in more than 20 engineering, has proven to improve the efficiency of design and analysis of hydropower hub buildings and the intelligence level of engineering construction and operation management, and overcome the difficulties of multi-professional collaboration in the design stage and low efficiency of multi-participant coordination in the construction stage.