<p>Microwave turntable imaging for industrial non-destructive testing or contraband detection shares similar imaging geometry with circular synthetic aperture radar (CSAR), but differs distinctly in imaging modality and signal processing. First, its ultra-short standoff distance requires continuous-wave (CW) transmission and a bistatic antenna configuration (to suppress transceiver crosstalk), replacing long-range Synthetic Aperture Radar (SAR)’s “stop–go” mode with a fixed-bistatic-angle CW mode. Second, its large field of view and wide antenna beamwidth cause near-field electromagnetic propagation with significant wavefront curvature, making conventional CSAR algorithms (relying on far-field plane-wave approximation) inapplicable—these induce severe phase errors, leading to range migration correction mismatch and image blurring/distortion. To reduce such errors, cut system costs, and improve resolution/computational efficiency, a circular convolution-based range migration algorithm (RMA) is proposed for slant-plane-to-ground-plane transformation in turntable near-field imaging. The system uses a fixed bistatic angle (BA) antenna pair for slant-plane sampling. The algorithm first compensates elevation-dependent phases to map echoes to an equivalent ground plane, then derives a matched filtering kernel via polar-coordinate spherical wave decomposition, circular convolution, and discrete Fourier transform (DFT) properties, and finally reconstructs images through multi-dimensional inverse DFT and STOLT interpolation. Point-target simulations, full-wave FEKO modeling, and laboratory tests confirm high-resolution imaging over a large bistatic angle aperture.</p>