<p>To investigate the mechanical response and energy consumption mechanism of frozen saline clay under dynamic impact loading, experiments were conducted on the dynamic mechanical behavior, failure morphology, and energy dissipation characteristics under different salt contents and impact air pressures, and the Johnson–Cook model was modified. The results show that higher salt content leads to a lower initial slope of the stress‑strain curve, a reduced elastic region, and weaker brittle behavior. The dynamic strength increases with impact air pressure but decreases significantly with rising salt content, exhibiting a clear salt weakening effect. For a given salt content, the dynamic strength growth factor increases linearly with impact air pressure; under a fixed impact air pressure, this factor first increases and then decreases with salt content. Specimens with low salt content mainly exhibit brittle crushing failure; those with medium salt content transition to splitting or shear failure, while high salt content specimens show viscoplastic bulging failure. The incident energy, reflected energy, and absorbed energy stabilize over time, and the absorbed energy decreases with increasing salt content. The energy reflection coefficient increases with impact air pressure but decreases with salt content; the energy absorption rate decreases with both increasing impact air pressure and salt content. Salt content governs the dynamic behavior and failure patterns by controlling the unfrozen water content and ice bonding strength. The proposed modified Johnson–Cook model reasonably captures the effects of impact air pressure and salt content on the strength characteristics of frozen clay.</p>