Fluorine-doped SrTiO3 powder was prepared by mechanochemical reaction and its photocatalysis has been studied in this paper. The photocatalytic experimental results show that the photocatalytic activity for nitrogen monoxide oxidation of SrTiO3 can be improved by fluorine doping in both visible light and near ultraviolet light range. The photocatalytic activities of SrTiO3 are ca. two and three times larger than those of pure SrTiO3 under the irradiation of wavelength longer than 510nm and 400 nm.