Titanium oxide films were prepared by micro-arc oxidation (MAO) on TC4 titanium alloy. The films with different phase structure were obtained by changing the forward voltage. The phase structure,surface topography and photocatalytic ability of titanium oxide films were characterized by X-ray diffraction, SEM and photocatalytic decoloration of methylene blue solution evaluated by visible-infrared spectrometer. The impact of phase structure on photocatalytic performance of titanium oxide films was analyzed. It is found that the relationship between mass fraction content of anatase and anodic voltage. When the mass fraction of anatase is 83. 98% , and the photocatalytic degradation of methylene blue solution arrives 31. 26% in an hour.