A series of MoS₂/ZnO compound photocatalysts with different mass ratios were successfully prepared by hydrothermal method. The X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and UV-vis absorption were used to characterize the prepared MoS₂/ZnO photocatalysts. It was proved that the combination of MoS₂ and ZnO can increase the content of oxygen vacancies on surface of ZnO, thus improving the light absorption capacity in visible light region and reducing the band gap of ZnO. And the photocatalytic performance of ZnO was improved. Experimental results show that the MoS₂/ZnO (3 wt%) compound has the highest degradation rate for methylene blue (MB) under visible light, which means that it has the best photocatalytic activity among all the prepared samples.