Abstract: Titanium dioxide (TiO₂), as an oxide semiconductor material of titanium, has been widely employed in light harvesting due to its stable chemical properties, high refractive index, and non-toxicity. However, TiO₂ only has a strong response to ultraviolet light due to its inherent wide bandgap. Here, a composite structural material (TiO₂/Au NWs) composed of titanium oxide nanowires and gold nanoparticles was fabricated through hydrothermal synthesis and magnetron sputtering processes. This innovative design synergistically integrates the light-trapping effect of TiO₂ nanowires with the localized surface plasmon resonance (LSPR) of Au nanoparticles, thereby significantly enhancing the broadband light absorption capacity and photothermal conversion efficiency of TiO₂ materials in the full spectral range (200 nm to 2500 nm). Through structural and compositional optimization, the developed TiO₂/Au composite nanowire architecture demonstrates exceptional broadband light absorption with consistent absorption rates exceeding 90% across the full spectrum (200 nm to 2500 nm), achieving a solar absorption about 95% and a surface temperature about 76°C under one-sun irradiation. The TiO₂/Au composite nanostructure design effectively extends the absorption spectrum of TiO₂-based materials while enhancing both photothermal and photocatalytic performance, thereby advancing the application of TiO₂ materials in solar thermal conversion and photocatalytic fields.