Abstract: Determining the influence of metal wires on interfacial energy transfer characteristics is crucial for the accurate assessment of lightning-induced damage. An experiment on return-stroke damage is designed using artificially triggered lightning with OGW (overhead grounding wires) to investigate the effect of metal wires on interfacial energy transfer under return-stroke current conditions. Through this experiment, characteristics of interfacial energy transfer, taking into account the influence of metal wires, are preliminarily determined. A modified laboratory platform for lightning test of return-stroke experiments is designed, and relevant data unaffected by metal wire and electrode jet are obtained. Finally, based on the injected energy inversion method, injected energy results are quantitatively compared for cases with and without metal wire. Further discussions are conducted on the influence of wire diameter and length on interfacial energy transfer characteristics. In an artificially triggered lightning experiment simulating a return-stroke process with one single return stroke and a lightning current amplitude of -32.9 kA, the analysis of the lightning stroke process and the resulting damage to OGW reveal that E_m remains smaller than E_r. Considering the influence of the metal wire, the difference in injected energy during artificially triggered lightning reaches 76.2%. In laboratory return-stroke experiments with low-melting-point alloys, all measured values of E_m are lower than those of E_r. Under the influence of the reference current waveform condition, the injected energy discrepancy in the experimental group with metal wires (0.2 mm in diameter, 15 mm in length) is 88%, while that in the control group without wires is 83.1%. These results indicate that the introduction of metal wires increases the injected energy during the return-stroke process under low current amplitudes, with an enhancement rate as high as 42.1%. The diameter and length of the metal wire are observed to influence the interfacial energy transfer characteristics. When the diameter of the metal wire increases from 0.1 mm to 0.3 mm (15 mm in length), the difference in injected energy increases from 84.3% to 91%. Similarly, when the length of the metal wire decreases from 20 mm to 5 mm (0.2 mm in diameter), the discrepany increases from 87% to 89.6%.