In this work, the simple hydrothermal method was used to prepare a series of ZnO /r-GO (ZGO-x) catalysts. The obtained products were subjected by a series of characterization, which showed that The zinc oxide particles were encapsulated on r-GO and the crystal structure was not disrupted. In addition, due to the large specific surface area and the good electrical conductivity of r-GO, more photogenerated electrons are rapidly transferred to the r-GO surface to participate in the reaction, thus improving the photocatalytic performance. The degradation rate of sample ZGO-3 reached 100% for RhB after simulated sunlight irradiation for 150 min, whereas the pure ZnO degraded RhB by about 83% under the same environment. The ZGO-3 also showed the best photocatalytic degradation of methyl orange, with 100% degradation in 180 min, whereas pure ZnO degraded only 87.64% of methyl orange under solar irradiation.