An improved two-step heat of hydration method was used to prepare a core-shell structured ZnO/ZnSe composite material. Zinc oxide nanoparticles were prepared with zinc acetate and diethanolamine,and a selenium-containing anion solution was prepared with selenium powder and sodium borohydride. The optimal condition of Zn∶Se=1.6∶1 was obtained by adjusting the ratio of raw materials,and a spherical core-shell structure was prepared. ZnO/ZnSe,combined with transmission electron microscope,X-ray powder diffractometer,ultraviolet-visible spectrophotometer,photoluminescence spectroscopy,X-ray photoelectron spectroscopy to characterize the material composition and morphological structure,and its photocatalytic activity is analyzed and studied.