The invention discloses a process for preparing a high efficiency nanometer Tio2 visible light catalyst codoped with metal and non metallic ion, belonging to the photocatalysis technology field. The invention adopts titanic acid ester as precursor, uses metal salt and non-metallic compound as dopant, in accordance with sol-gel method, prepares the nanometer TiO2-based photocatalyst with codoping, high efficiency and visible light catalytic activity, wherein the catalytic activity is greatly higher than that of single-doped TiO2-based catalyst. The invention is characterized by the following: 1. due to codoping of the metal and non metallic ion, discrete localized doping level is formed respectively on the lower part of the conduction band energy level and the upper part of the valence band energy level of the TiO2-based catalyst, thus increasing the absorption of visible light and greatly improving the catalytic activity; 2. the doping level can inhibit the recombination of photogenerated carrier, promote the probability of the photogenerated carrier entering into the photocatalytic reaction and efficiently degrade pollutant molecules.