Au-coated TiO2 Nano-thin films are prepared by radio frequency (RF) sputtering and then Au ion is sputtered on glass substrates. The structural and the surface morphology of Au-coated TiO2thin films are investigated by X-ray diffractometer (XRD),scanning electron microscope (SEM),etc. The results show that the TiO2 films with smooth surface consist of anatase TiO2 nano-particles with 200 W sputtering power. The diameter of nano-particle is in the range of 20-100 nm. The surface morphology has not been changed by Au ion sputtering and vacuum annealing. The photocatalytic sterilizing capability of the films is measured by Newcombe experiment. The results show that photocatalytic sterilization of the Au-coated nano-composite TiO2 thin film is enhanced compared with the single TiO2 film in the photocatalytic disinfection range,speed,and efficiency. Its killing rate to Bacillus subtilis in 10 min can achieve 90%. Based on the test results,the photocatalytic bactericidal mechanism of Au-coated TiO2 thin film is discussed.