Abstract: ‍ ‍Aircraft stealth design is a key link in the overall design of advanced aircraft. As more complex structures and emerging composite materials are applied to aircraft manufacturing， the analysis of electromagnetic scattering characteristics based on scaled models becomes no longer accurate. Carrying out near-field imaging and diagnosis of electromagnetic scattering characteristics of full-scale aircraft in indoor or outdoor small areas has become an important way to evaluate stealth characteristics with high efficiency， It has received extensive attention at home and abroad. In this paper， two typical aircraft near-field imaging geometries are introduced. Based on the spherical wave decomposition theory， the signal models are established respectively， and the frequency-domain imaging processing algorithm is derived. The corresponding imaging processing processes of two different imaging geometries are compared and analyzed. It is proposed that sub aperture imaging processing is the basic strategy for analyzing aircraft electromagnetic scattering characteristics； The differences and relations between planar array 3D imaging and cylindrical array 3D imaging in imaging processing complexity， point spread function and application characteristics are summarized. The correctness of the proposed signal model and processing algorithm is verified by three-dimensional imaging of simulation data.