In this study, based on the sol-gel spin coating method, aluminum and nitrogen co-doped TiO2 film samples were prepared with aluminum doping amount of 3.00at%, and nitrogen doping amount of 6.00at%, 7.00at%, 8.00at%, and 9.00at%, respectively. The test results of the samples show that the basic structure of TiO2 is still retained in the co-doped samples, and the grain size of aluminum and nitrogen co-doped samples is reduced to different degrees, which makes the surface of the samples modified to become more uniform and flat compared with that of the undoped. The co-doped samples showed different degrees of red shift and enhanced absorbance in both UV and visible regions. When the doping amount of nitrogen is 7.00at%, the diffraction peak of (101) is the largest, the peak type is the sharpiest, and the obtained TiO2 film has the best optical performance. Compared with the eigenstate TiO2, the band gap values of the co-doped samples are decreased, and the minimum value is 2.873eV. The above results indicate that Al/N co-doped TiO2 film can improve its optical properties.