In order to improve the ocean-going strategic delivery capability of naval aviation, a carrier-based reconnaissance and attack UAV is conceptually designed, and its stealth characteristics are analyzed. The 3D digital prototype is conceptually designed by using CATIA(computer aided three-dimensional interface application) software.The scattering of a triangular surface source is calculated based on the physical optics method, and the diffraction of the wedge edge is calculated based on the equivalent current method. The stealth characteristics are analyzed by combining the two methods, and the radar cross section (RCS) scattering characteristics of the aircraft are numerically simulated. The experimental results show that the 3D digital prototype of aircraft can be designed efficiently by using CATIA software, which can be used to demonstrate the aircraft design scheme, and the RCS calculation method can calculate the RCS scattering characteristics of complex aircraft efficiently.