Abstract: The PO method is presented for solving the EM scattering from the electrically large complex martialtargets-missile and flight. According to the property of MPI, the occlusion identification is parallelized through cyclicallyscheduling the PO triangles to different processes by their numbers. Taking simple sphere for example, the parallel speedupfactor is shown by comparing the computational time of different processes, which proved the efficiency of the parallel method.Then, the instance for solving RCS of the missile and flight targets with electrically large size is given. The modeling andtriangular meshing of the real martial targets are investigated by FEKO. Based on the MPI of PC clusters, the parallel PO isapplied for obtaining the RCS of the missile and flight targets. The results validate the effectiveness and correctness of themethod.