In this paper, zinc oxide quantum dots (ZnO QDs) were synthesized using the sol-gel method, and loaded onto cerium oxide microspheres (CeO2) through an impregnation process, resulting in the preparation of ZnO QDs modified cerium oxide binary composite material (ZnO QDs/CeO2). The structure and morphology of the composite material were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM), and other methods. The efficiency of the degradation of rhodamine B was tested under visible light, and the photoelectrical performance of the composite material was characterized using EIS、UV-vis. The experimental results are as follows: the diameter of ZnO QDs was 6-9 nm, the diameter of CeO2 microspheres was 800 nm, and ZnO QDs were uniformly distributed on the surface of CeO2, extending the light response range of the composite material to 550 nm. The efficiency of the ZnO QDs/CeO2 composite for the degradation of rhodamine B under visible light was twice that of CeO2. Through the study of the constitutive relationship, it was found that the introduction of ZnO QDs led to an increase in the light absorption range of the composite material and an improvement in the efficiency of photoinduced electron-hole separation, demonstrating outstanding photocatalytic performance.