Ag antidot arrays modified TiO2 films are obtained by PS colloidal crystal template technique and magnetron sputtering method, and the microstructure of Ag antidot array is modulated through controlling the sputtering power. And then, the structural and the photocatalysis performances of all samples are characterized by using scanning electron microscopy, X-ray diffraction, UV-Vis spectrophotometer, and four-point probe. The experimental results show that the microstructure of Ag antidot array significantly influences the photocatalysis performance of the sample. With the diameter of the antidot array decreasing, the photocatalysis performance of the sample is enhanced due to the increase of conducting ability. The photocatalysis performance is highest, when the diameter of the antidot array is 710 nm. Subsequently, with the diameter of the antidot array further decreasing, the photocatalysis performance decreases to a certain extent, which results from the increases of the carrier loss and the light shading area. The photocatalysis performance of Ag antidot array modified TiO2 film is superior to that of TiO2 film. This is attributed to the fact that the Ag antidot array could effectively promote the separation of surface photoinduced charge carrier of TiO2 nanoparticles, which is responsible for the remarkable increase in photocatalytic activity.