The invention relates to the technical field of engineering cost, in particular to a BIM-based whole-process engineering cost consultation system, which comprises a BIM model construction unit, a costmanagement unit and a user experience unit, and is characterized in that the BIM model construction unit is composed of an information data acquisition module, a BIM database module and a Revit modeling module; the BIM database module is in butt joint with the background database to transmit data, and the cost management unit comprises a project estimation module, a project rough calculation module, a construction drawing budget module, a completion settlement module, a real-time price collection module and a project progress control module. And the user experience unit comprises a real-timeprice change query module, a 3D model development module and a user feedback module, the real-time price change query module adopts a real-time information prompt mode, and the 3D model development module adopts a holographic projection technology. According to the invention, comprehensive consultation experience can be provided for customers, and the customers can know the real-time cost change situation in time.