This paper introduces the BIM forward design process of the Tseung Kwan O desalination plant in detail, and elaborates on the project BIM forward design workflow, BIM application points, and the creation and use of project CDE. Moreover, comparing BIM forward parametric design with traditional design, it is highlighted that BIM forward design can achieve the integration of design and construction, efficient and complete design information transmission, intuitive project design, and convenient and fast drawing updates. The paper also reveals that although applying BIM technology, the traditional design still keeps its stubborn, that is, blindly using the single function of BIM technology to assist traditional design and disconnects design and construction. What's more, this paper also takes advantage of BIM forward design to briefly introduce its characteristics: efficient and complete transmission of building information from the design stage to the construction and operation stages, and the continuous modification and enrichment of building information at each stage, etc.