The cylindrical Floating Production Storage and Offloading (FPSO) typically adopts a bulwark between the main deck and the process deck, but it is prone to suffering serious slamming loads under high sea conditions. In order to design a bulwark that balances strength requirements and weight control, taken the cylindrical FPSO used in Liuhua 11-1 Oilfield Continued Development Project as an example, the method that combines theoretical calculation with finite element analysis is applied, the volume of the local calculation model is set as the optimization goal and the adoption of different boundary conditions is regarded as the optimization approach to propose a structure analysis method for the inclined bulwark that can balance the design efficiency and calculation accuracy. It is determined that the minimal area of 6 m×6 m is taken as the loading range of the slamming loads when conducting local verification of the bulwark, and it is extended to the interval of the adjacent strong girder position, which is used as the selection scope of the model. This scheme is successfully applied in the existing engineering practice and can also provide useful references for similar structural design work.