Abstract: As the core function system of pumped storage power stations, the design scheme of water transmission and power generation system directly affects the power generation efficiency and reliability of a power station.Aiming at the prominent problems in the current scheme design of water transmission and power generation system of pumping and storage power stations, such as the lack of overall consideration on 3D spatial relationship in line design, the deficient linkage and feedback relationship between design calculation and system design, and less quantitative data as decision-making support for scheme comparison and selection, based on the 3DEXPERIENCE platform, we propose a comparison and selection process of 3D scheme design for water transmission and power generation systems.In the process, we conduct functional development and analysis around 3D design and quantitative optimization of water transmission and power generation system scheme, in which 3D design and design calculation are integrated organically, and we customize a design module for water transmission and power generation system of pumping and storage power stations.Finally the design process was applied to the preliminary design of ZY pumped storage power station.The application results show that the design process can realize the 3D line layout, linked and rapid calculation and intuitive quantitative comparison among multiple schemes of water transmission and power generation system design, effectively improve the rationality and design efficiency during scheme design, so it provides certain technical support for the 3D forward design and scientific decision of design schemes of pumped storage power stations.