Abstract: With the development of radar technology, radar-guided weapons pose serious threat to the safety of ship targets on the sea surface. In order to protect the safety of ships in sea routes, polyhedral angle reflector is widely used. With the combination of sea ship target and angle reflector array as the analysis target, local iterative physical optics method is proposed to achieve reliable electromagnetic scattering modeling as for the target scattering characteristics with strong scattering effect and strong local coupling effect. Through the fast multipole method (FMM) technology and GPU parallel technology, the fast RCS simulation calculation of complex target and angle reflector arrays on the sea surface in large scenes can be realized. In this way, the unknowns of the cyclic calculations in the iterative physical optics method to analyze the interactions arising from the electromagnetic scattering process of complex targets are reduced, and the current iterative solution for the radiation effect is truncated in the local region around the ray path. Additionally, this method takes into account the influence of edge diffraction fields on the target’s RCS and utilizes diffraction fields to correct the surface reflection field. Simulation results for different types of sea surface ships with reflector arrays demonstrate the effectiveness of the proposed method as a practical solution for electronic reconnaissance in naval warfare scenarios.