NOVELTY - A nanometric orderly structured photoelectric conversion composite film comprises titanium dioxide nanometric short bar orientation arrays embedded in single-crystal rutile structure among the titanium dioxide nanoparticles in sol-gel anatase structure. The composite film has a thickness of 120-250 nm. A single nanometric short bar in the nanometric short bar arrays has a diameter of 20-60 nm, and length of 120-250 nm. The single anatase nanoparticle has particle size of 20-30 nm.    USE - A nanometric orderly structured photoelectric conversion composite film for use in solar battery and power assistant photocatalysis.    ADVANTAGE - The orientation of single-crystal nanometric short bars provides the quick passages of transferring the photo-production electrons to the conducting matrixes. The composite film is prepared by a method that is simple and easy and that has good repeatability; is even, and has excellent crystallization, high purity and good photoelectric conversion performance.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing the composite film, comprising preparing an acid washing liquid comprising hydrofluoric acid, nitric acid, and de-ionized water at volume ratio of 1:3:6; preparing precursor containing tetravalent titanium ion; preparing single-crystal rutile nanometric short bar orientation array film; preparing titanium dioxide sol by utilizing diethanolamine, tetrabutyl titanate and ethanol at mass ratio of 1:138-3.2:8.2-8.6 which is stirred with a mixture of deionized water (5.6-5.9 mass%) and ethanol (45.5-46.5 mass%); and preparing the composite film by immersing substrate of single-crystal rutile nanometric short bar orientation array film covered on matrix surface in titanium dioxide sol at relative humidity of 20-25%, vertically drawing the film at drawing rate of 4-8 mm/s, and naturally drying at 400-500 degrees C for 1-2 hours. The matrix can be metals, conducting glass or conducting polymers.