N, Al doped TiO2 and N, Al co-doped TiO2 composites were prepared by sol-gel method, respectively. The photocatalytic degradation efficiency of dyes methyl orange, methylene blue and rhodamine B under visible light was studied. The catalysts were characterized and evaluated by XRD, SEM, XPS, UV-Vis DRS, and N2 adsorption-desorption. The experimental results show that the crystal structure of N, Al co-doped TiO2 remains as anatase, the specific surface area increases, and the agglomeration phenomenon slightly decreases. N, Al co-doped TiO2 catalyst has the best degradation effect on methyl orange under visible light, and the decolorization rate can reach 70%.