Metal nanocrystals with unique surface plasmon resonance (SPR) are a good wide bandgap semiconductor visible light sensitized material. In this study, 0.3% mole ratio gold-modified titanium oxide (Au/TiO2) nanocomposite was synthesized by solvothermal and calcination. The as-synthesized Au/TiO2 nanocomposite was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), andultra-violet-visible (UV-vis) analysis. The results showed that the Au nanoparticles could significantly improve the visible light absorption properties of TiO2 at this lower content due to the strong surface plasmon resonance effect. With the increase of the calcinated temperature, the visiblelight absorption peak changed from ~ 550 nm to 670 nm, which is better for usage of the solar spectrum. The antibacterial activityfor Escherichia coli (E. coli) of Au/TiO2 nanocomposite shows that the mixed crystal Au/TiO2 with anatase and rutile phase, calcinated at 450 ℃, have the highest photocatalytic activity.