In order to degrade the pollutants in water and atmosphere by the photocatalysis technology, the invention discloses a method for preparing a high activity non-metallic ion co-doped titanium dioxide photochemical catalyst. In the photochemical catalyst, titanium ester or titanate is used as a precursor, non-metallic compound comprising boron, carbon, nitrogen, fluorin, silicon, phosphor, sulfur, chlorine, bromine, iodine, and the like, are used as doping agents, the high activity non-metallic ion co-doped titanium dioxide photochemical catalyst is prepared by adopting the sol gel method. Compared with a titanium dioxide photochemical catalyst single-doped with pure titanium dioxide and the non-metallic irons, the visible light catalytic activity of the titanium dioxide photochemical catalyst on the degradation of parachlorophenol is greatly improved, and the ultraviolet light catalytic activity can also exceed the catalytic activity of the pure titanium dioxide catalyst. The method also has the advantages that the preparation technique is simple, the equipment requirement is low; the particle diameter of the product is small, the specific surface is relatively high, the dispersivity is good, thus having a wide application prospect in the environmental cleaning scientific field.