Zr-based amorphous alloys possess excellent glass-forming ability and high energy density, which facilitate the development of new energetic fragments. However, their poor plasticity limits their application in fragment-based systems. This study aims to investigate the Zr-Al-Ni-Cu alloy system by substituting Hf for Cu to examine its effects on the glass-forming ability and mechanical properties of Zr₅₅Al₁₀Ni₅Cu_{30 - x} Hf _x (x = 0, 1, 3, 5, 7, 10, atomic fraction, %) bulk metallic glasses (BMGs). The investigation used XRD, DSC, SEM, and a universal testing machine for characterizing the alloy system. Results demonstrate that moderate Hf substitution for Cu enhances the glass-forming ability, thermal stability, and compressive ductility of Zr₅₅Al₁₀Ni₅Cu₃₀ BMGs. With an Hf content of 7%, the alloy achieves a maximum critical diameter of 12 mm and an expanded undercooled liquid phase interval of 85 K. With an Hf content of 5%, the alloy achieves a critical diameter of 10 mm, an undercooled liquid phase interval of 75 K, and substantially improved compressive plastic strain of 13.3%, thereby enhancing its performance compared with the original composition. Spherical specimens of Zr₅₅Al₁₀Ni₅Cu₂₅Hf₅ with a diameter of 9.4 mm were prepared using vacuum suction casting, followed by quasi-sealed chamber impact overpressure experiments. The results indicate that the critical overpressure velocity of the specimens is approximately 600 m/s, and an impact velocity of 1360 m/s produces a maximum overpressure peak of 0.3291 MPa, where the specimens achieve a peak energy release efficiency of 63.17%.