Abstract: In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance, a narrow band gap semiconductor MoS _2 and organic macromolecular cucurbitnurils (Qn) were used to modify CdS. Qn/CdS-MoS _2 (n=6, 7, 8) composite photocatalysts were synthesized by hydrothermal method. Infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, ultraviolet-visible and photoluminescence spectrum were used to characterize the structure, morphology and optical properties of the products, and the catalytic degradation of the solutions of methylene blue, rhodamine B and crystal violet by Qn/CdS-MoS _2 composite catalyst was investigated. The results showed that the Qn played a regulatory role on the growth and crystallization of CdS-MoS _2 particles, Qn/CdS-MoS _2 (n=6, 7, 8) formed flower clusters with petal-like leaves, the flower clusters of petal-like leaves increased the surface area and active sites of the catalyst, the Qn/CdS-MoS _2 barrier width decreased, the electron-hole pair separation efficiency was improved in the Q6/Cds-MoS _2 . Qn makes the electron-hole pair to obtain better separation and migration. The Q6/CdS-MoS _2 and Q7/CdS-MoS _2 have good photocatalytic activity for methylene blue, and the catalytic process is based on hydroxyl radical principle.