The flexibility of UAV in structural style and material composition makes it have more space for stealth performance optimization than the manned aircraft, so it was urgent to carry out near-field imaging indoors or outdoors. Based on the imaging geometry model of aircraft turntable, a general signal model of near-field turntable imaging was established, and a near-field frequency-domain imaging algorithm for aircraft electromagnetic scattering feature diagnosis was proposed. Under the constraint of sub aperture imaging setting, the slant plane spectrum was approximately processed as the horizontal plane spectrum; the applicable conditions of the algorithm was analyzed, and simulation data around typical near-field imaging geometry and aircraft size was generated.The completes near-field imaging in the range of 0.6~35 GHz was performed. Good imaging results confirm the correctness of the theoretical analysis and the proposed algorithm.