Numerical simulation of spherical convergent flap nozzles with different trailing edges shaping measures was finished using the self-developed electromagnetic scattering characteristic program based on the ray-tracing method. Radar cross section (RCS) of inner cavity scattering field and edge diffraction field was obtained for above several different SCFN. Meanwhile

induced electric current of inner cavity wall at different azimuth angles was calculated. With the method of analyzing the induced electric current

the change law of RCS was explained essentially. The analysis results show that the shaping measures for the trailing edge of the nozzle have a significant and obvious effect on decreasing the RCS of edge diffraction field and improving the electromagnetic stealth performance. Compared with ordinary occultation algorithm

the ray-tracing method shortens computational cycle by 21%

and improves the computing efficiency obviously. The analysis method using induced electric current can explain the change law of RCS clearly and intuitively with a high reliability.