Abstract: Clarifying the dynamic mechanical response and localized instability mechanism of metallic glasses under high-temperature and high-strain-rate conditions is essential for understanding their plastic deformation, shear-band evolution, and catastrophic failure behavior. Quasi-static and dynamic compression tests were conducted on Zr_41.2Ti_13.8Cu_12.5Ni₁₀Be_22.5 bulk metallic glass over a strain-rate range of 10⁻³ s⁻¹ ~ 3000 s⁻¹ at 298 K, 673 K, and 873 K, corresponding to the room-temperature glassy state, supercooled liquid region, and crystallization-sensitive temperature region, respectively. The fracture morphologies of the recovered specimens were further characterized by scanning electron microscopy. The failure mechanism of the material was also analyzed by integrating the stress-failure model with the temperature-softening model. The results show that at 298 K and 673 K, the failure stress decreases markedly when the loading condition changes from quasi-static to dynamic compression and then tends to stabilize at higher dynamic strain rates, while the failure strain under dynamic loading is generally lower than that under quasi-static loading. At 873 K, the specimen under quasi-static compression does not exhibit macroscopic shear fracture within the tested strain range, whereas unstable failure still occurs under dynamic loading. Meanwhile, the failure strain remains at a relatively high level, indicating a marked change in deformation and instability mode. Fracture morphologies of specimens recovered at a representative strain rate of 2586 s⁻¹ show that localized shear features dominate at 298 K, sliding and local melting features are most pronounced at 673 K, and the cell-like vein patterns become more uniformly distributed at 873 K with a reduced fraction of molten regions. Strain energy density and normalized local thermal instability coefficient analyses indicate that the alloy exhibits higher deformation energy absorption before failure at 873 K, while the energy dissipation becomes more dispersed. Combined with the strain-rate-correlated softening model and temperature-softening correction, the reduction in failure stress at 673 K is mainly attributed to high-temperature softening, whereas the failure stress at 873 K first increases and then decreases slowly with increasing strain rate, suggesting an additional effect of structural-state evolution on dynamic failure. These results indicate that temperature governs the dynamic compression response and localized instability mode of the Zr-based bulk metallic glass by regulating high-temperature softening, shear localization, structural-state evolution, and energy dissipation pathways.