Abstract: To address the problem that the formation of high-strength and reliable joints between alumina ceramics and metals is restricted, which becomes a key bottleneck for their applications in fields such as electronic packaging, energy and power, and aerospace, the interfacial bonding characteristics of Ag(111)/Al₂O₃(0001) and the doping behaviors of four active elements, Ti, Zr, V, and Hf, were systematically investigated using a first-principles calculation method. The results indicate that an interface model constructed with a seven-layer Ag(111) surface and an eleven-layer Al₂O₃(0001) surface is the most stable, with a lattice mismatch of 3.38%. The adhesion work calculations reveal that the bonding strength of the O-terminated interface is significantly higher than that of the Al-terminated interface; after doping with active elements, the interfacial adhesion work is notably enhanced, with the activity order of Ti—V—Zr—Hf Hf. Electronic structure analysis indicates that significant charge transfer occurs between the active elements and O atoms, forming strong covalent–ionic hybrid bonds; the p and d orbitals of the active elements strongly hybridize with the s and p orbitals of O, thereby improving the bonding performance at the interface between the silver-based filler metal and Al₂O₃. This study provides a theoretical basis for optimizing the interface of ceramic/metal heterogeneous joints using silver-based active filler metals.