Radar cross section (RCS) calculation is an important issue of objects stealth and identification. It is necessary to design the RCS software because of the high cost of RCS measurements in practice. In this paper, designing of efficient software using physical OPTICS theorem for radar cross section calculation of the complex perfect electric conductors or complex dielectric objects for high frequencies is investigated. In this method, first the object will be meshed in Abaqus Software. Then the obtained data of every mesh is transferred to MATLAB Software and, after that, the physical OPTICS theorem is applied for every mesh, with considering the summation of electric fields that is seen from each mesh. As the result, the radar cross section of total object will be obtained. Simulations results show the proposed method has good agreement with CST-MS results and determines the RCS of the objects with lower complexity in the lower time consuming.