Abstract: Design and construction are unity of opposites and inseparable in a project.However,for some water conservancy projects in China,the two stages are generally separate,resulting in the poor control of time,quality and cost of a project.To use BIM technology to assist the integration of design and construction,improve project management precision,successfully transferring the design BIM model to the construction stage is the basis.Based on a pump-gate project in the renovation project of south extension section of Zhangjing River,this paper studied the link-up and application of the mainstream BIM platform Autodesk(referred to as A platform)and Bentley(referred to as B platform)in the water conservancy project,and verified the feasibility of using B platform to establish design model and then extend to the construction stage in A platform.At the same time,it summarized the “most cost-saving” technical route from the design stage to the construction stage,which can avoid blind secondary development or software purchase,and provide reference for the selection of BIM software and the integration of design and construction of BIM technology.