Abstract: Facing the complexity of hydropower projects, the present BIM technology has disadvantages of low standard level and fuzzy process. In the survey and design stage of Huangjinxia Hydro-complex project, based on Dassault 3DEXPERIENCE platform, the online collaborative application process and methodology is studied, and a set of BIM based design process system for hydropower projects is formed. Combined with the BIM design process, the parametric modelling, statistic of project quantity, 3D drawing, we summarize the difficulties and innovations in the application process of BIM. Finally, we study the attribute extension and digital delivery, providing new ideas for information transmission during the whole project cycle. The project practice shows that the research results have improved the design efficiency and quality.