CuCr2O4 nanoparticles have been successfully synthesized via a facile citric acid (CA)-assisted sol-gel method, and further combined with TiO2 by solid phase method. These obtained photocatalysts were characterised by X-ray diffraction (XRD) and UV-vis diffuse reflectance spectrum (UV-vis DRS). Then the photocatalytic inactivation of Escherichia coli, a Gram-negative bacterium, was performed with the photocatalysts to investigate the photocatalytic bactericidal capability under simulated solar light irradiation. The results show that CuCr2O4/TiO2 composite photocatalysts exhibited a much better photocatalytic activity than either pure CuCr2O4 or TiO2, and in the composites, the effects of CuCr2O4 to TiO2 mass ratio and calcination temperature on bacterial photocatalytic inactivation were investigated in detail. With a 90% content of TiO2, calcination temperature at 500 ◦C, the optimal photocatalytic sterilization amount of CuCr2O4/TiO2 is 1.62 and 1.33 times more than that of CuCr2O4 and TiO2, respectively. And Escherichia coli were almost completely inactivated within about 40 min.