In this study, the swelling resistance of W/Cu nanocomposites is investigated after helium irradiation at RT and 400 °C. The results show that W/Cu nanocomposites with interface structure present better resistance to helium swelling as compared with W monolayer. The PAS results reveal that the unique interfacial structure of W/Cu nanocomposites effectively improves the recovery of vacancy-type defects under He+ irradiation, which results in good resistance to irradiation swelling. This result shows that introducing interface structure can effectively enhance the swelling resistance of materials and sheds light on the design of radiation-tolerant materials for advanced nuclear reactor applications.