The invention, which belongs to the polymer solar battery technology field, relates to a cathode modified material of a polymer solar battery and a battery using the modified material. The polymer solar battery comprises a substrate, an anode layer, an anode modification layer, a photoelectric active layer, a cathode modified layer and a cathode layer, wherein the above-mentioned layers are successively stacked; the cathode modification layer is an acetylacetone titanium oxide film; and the cathode modification material is acetylacetone titanium oxide. According to the invention, acetylacetone titanium oxide is used as a material of a cathode modification layer; a spin coating method is employed to prepare the cathode modification layer; the acetylacetone titanium oxide is introduced into a polymer solar battery, so that high efficient collection of electrons is realized. Moreover, compared with current titanium dioxide prepared by a sol-gel method and LiF obtained by vacuum evaporation, the acetylacetone titanium oxide enables the polymer solar battery to have characteristics of high photoelectric conversion efficiency, simple technology, low cost, and good experiment repetition and the like; besides, the polymer solar battery is suitable for large-scale industrialized production.