Herein, the CuInS2/ZnS/TGA quantum dots (QDs) were prepared by the oil phase reaction containing thioglycolic acid (TGA) as a functional modification agent under a nitrogen atmosphere. The CuInS2/ZnS/TGA QDs using as the photocatalysts exhibited high photocatalytic activity for the degradation of Rhodamine B (RhB) under ultraviolet irradiation. The photocatalytic conditions were optimized to degrade RhB with superior performances, including the initial RhB and CuInS2/ZnS/TGA QDs concentrations, solution pH values and ultraviolet light intensities. Furthermore, the kinetic equations of photocatalytic reaction and possible photocatalytic degradation mechanism were investigated. The results indicated that it belongs to the typical first order kinetic in accordance with the Langmuir-Hinshelwood mechanism, and the electrons and holes on the surface of the CuInS2/ZnS/TGA microspheres are the main acting forces during the RhB photocatalytic degradation.