SO2-4/CeO2-TiO2 composite oxides were prepared with sol-gel and impregnation method. The structures and properties of the as-prepared samples were characterized with X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), pyridine adsorption infrared spectroscopy (Py-FTIR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Valence band X-ray photoelectron spectroscopy (VB-XPS) and photo-luminescence(PL) spectroscopy. The photocatalytic activity of the samples was tested through the reaction of the hydrogen production from water splitting. The results of XRD and FTIR and PL revealed that the heterojunctions were formed into CeO2/TiO2 phase junctions, which was conducive to promoting the separation of photo-generated electrons and holes. Py-FTIR spectra showed that Lewis acid site was formed on the surface of the SO2-4/CeO2-TiO2 composite, while formation was attributed to the SO2-4 coordinated to metals on the sample surface. The induced effect of SO led to an increase in the electron accepting ability of the surface metal ions and thereby further enhanced the separation of the photogenerated carriers. The UV-Vis and VB-XPS spectroscopy results showed that the semiconductor composites could narrow the bandgap and expend the light response range. The Lewis acidity affected the band structure of the composite oxide and made the position of conduction band minimum move to a more negative direction, which improved the photocatalytic reducibility of the catalyst and contributed to the improvement of hydrogen production activity. The results of hydrogen production from water splitting showed that the photocatalytic activity of SO2-4/CeO2-TiO2 composite oxide was better than that of pure CeO2, TiO2 and the CeO2-TiO2 composite oxide without the impregnation in sulfuric acid, and the average H2 yield rate was 1 934.1 μmol·g-1·h-1 in 5 h. The results of spectral analysis combined with photocatalytic activity of hydrogen evolution showed that the synergetic effects of heterogeneous structure of SO2-4/CeO2-TiO2 composite oxide and the acid impregnation promoted the photocatalyst activity.