A BIM (Building Information Modeling)-based water conservancy and hydropower project management cloud platform comprises a data acquisition layer, a communication network layer, a data resource layer, an application support layer, and a service application layer. The data acquisition layer includes project information management and spatial information measurement; the communication network layer includes a local area network, a VPN (Virtual Private Network) or a public network; the data resource layer includes a BIM model which is stored in a public cloud, in a private cloud or in a hybrid cloud and includes a BIM integrated database; the application support layer includes a BIM project management platform and a data exchange platform; and the service application layer includes BIM information query, construction process BIM management and BIM information output. The BIM integrated database is connected with different project object data, processes and resources, is a digital expression of construction facilities which contains rich data, is object-oriented and has intelligent and parametric characteristics, and supports dynamic information creating, sharing, updating and managing in the life cycle of a project.