<p>First-principles calculations were used in the study to reveal the role of the Ni intermediate layer in the interface strengthening effect of Fe/Cu bimetallic materials. <i>γ</i>-Fe/Ni, Cu/Ni, and <i>γ</i>-Fe/Cu interface models were constructed. The electronic structure, chemical bond properties, and charge distribution patterns at these interfaces were systematically analyzed. The results showed that the work of adhesion (<i>W</i>_ad) of <i>γ</i>-Fe/Ni and Cu/Ni was significantly higher than that at the <i>γ</i>-Fe/Cu interface. Additionally, charge accumulation between interface atoms was more continuous, and interactions were more pronounced. Significant hybridization also occurred between the 3d orbitals of the Fe and Cu atoms at the interface and the Ni atoms’ orbitals. These findings confirm that the Ni interlayer significantly enhances the bonding stability of the <i>γ</i>-Fe/Cu interface by optimizing interfacial wettability, strengthening the charge coupling interactions, and promoting 3d orbital hybridization. These findings provide a sound theoretical basis for the design and preparation of high-performance Fe/Cu bimetallic materials.</p>