First-principles simulations were conducted to investigate the micromechanics, thermodynamic, and electrical characteristics of L1₂-Al₃Zr/Al alloy. The computional results show that the interface with bulk-like atomic organization possesses excellent adhesion and the highest interface strength. During the machining process, the interface system preferentially fails at the Al side. According to the non-relaxation tensile test results, the L1₂-Al₃Zr(001)/Al(001) interface system has the highest tensile stress (16.78 GPa). However, after the relaxation tensile test, the L1₂-Al₃Zr(110)/Al(110) interface system has the highest tensile stress (10.18 GPa). Additionally, covalent and metallic bonds are generated between the atoms at interface based on the differential charge density and electronic localized function. The formants of interfacial atom orbitals show that the Al and Zr interface atoms have s-p-d or s-p hybridized orbitals.