Abstract: Aiming at the demand for digitalization by recent hydropower development in China, the application architecture of a cascade hydropower project digital river basin system has been designed and elaborated, and implementation principles of this complex system are formulated and discussed from four aspects: techniques, methods, ideas, and resources. Finally, we describe the practical implementation and achieved results of the digital project, digital migration, digital hub area, and digital reservoir system by China Three Gorges Corporation in engineering practice of hydropower development on the Yangtze River and the Jinsha River. Our results would be applicable to the design and construction of similar projects worldwide.