Abstract: In radar cross section (RCS) measurements of low-scattering targets, the structural properties and scattering effects of the target support pylon are key factors affecting measurement precision and data accuracy. Through electromagnetic simulation and imaging analysis, this work investigated the scattering mechanism of a baseline metallic support pylon and, for different polarization conditions, proposed a low-scattering optimization design for vertical support structures. A curved-surface structure is introduced into the support pylon, whose profile is optimized via shooting-and-bouncing-ray (SBR) simulations, reducing the HH-polarized scattering to below −15 dBsm over 0.5～20 GHz. Sawtooth-shaped grooves loaded on the pylon surface further suppress the scattering, bringing the minimum in-band level below -35 dBsm. On this basis, the protrusions are filled with radar-absorbing material (RAM) and capped with a curved metallic cover; full-wave simulations confirm that this integrated design markedly reduces scattering and background interference over 0.5～14 GHz. Measurements on a fabricated prototype demonstrate that the simulation-designed curved-surface structure combined with RAM achieves a forward scattering reduction of 21～33 dB at X-band. Compared with the baseline support pylon prototype, the optimized design achieved a markedly better RCS reduction; the proposed novel multifunctional support structure maintains essential load-bearing capability while remaining suitable for low-scattering test environments.