Abstract: To address the limitations of conventional polyurethane foam suspension systems, which tend to amplify occipital pressure and head acceleration under blast loading, a helmet suspension system based on a hard–soft dual-phase auxetic architected material is proposed. The system consists of a re-entrant auxetic hard phase coupled with a nearly incompressible soft phase. Under blast loading, the in-plane contraction of the auxetic hard phase squeezes and constrains the soft phase, converting part of the through-thickness input into transverse deformation and transverse kinetic energy, thereby enabling load redirection and pressure peak attenuation. Shock tube experiments demonstrate that, compared with auxetic and polyurethane foam suspension systems, the proposed dual-phase auxetic suspension system with an optimized array configuration significantly reduces key protective metrics, including head linear acceleration, angular acceleration, and occipital pressure.