In view of the problems faced in the construction of Floating Production Storage and Offloading (FPSO), based on the Product-oriented Work Breakdown Structure (PWBS) theory, a refined work breakdown method towards Work Package (WP) and Work Order (WO) is proposed, and a breakdown structure divided into intermediate products as objects and by work type and work category is established. A deepwater FPSO is taken for example to break down its construction work by taking the work stage as the main line, and a universal work breakdown system towards FPSO is formed, which provides feasibility for realizing the lean construction of FPSO.