In order to solve the performance limitations of traditional ship-type and prismatic FPSO, a novel concept of docking pyramidal FPSO is presented. For the new floating body, five independent shape parameters are presented to decide the geometry of floating body and also affect the basic functions and hydrodynamic performance of FPSO. Then boundary element method based on potential flow theory is applied to analyze the motion response of docking pyramidal floating body in wave. Furthermore, the effect of shape parameters on the hydrodynamic performance of FPSO is qualitatively studied, and the design guideline of the new floating body is also proposed to improve the heave motion performance based on wave potential flow theory and engineering approximate method. Finally, the new floating body can be designed according to the basic functions of an octagon FPSO, and the comparison results show the performance advantages of docking pyramidal FPSO and the rationality of design principle in this paper provide effective engineering equipment and solutions for deep-water oil and gas development.