Abstract: In order to obtain photocatalytic material with better catalytic activity to realize efficient degradation azo dyes, sulfydryl kaolin coated CeO₂-CdS was synthesized using sodium thioglycollate as sulfur source and modifier of kaolin. The optimum synthesis conditions of the as-prepared materials were confirmed by using photocatalytic degradation of crystal violet as model reaction. The as-prepared materials were characterized by X-ray diffraction, scanning electron microscope, transmission electron microscope, UV-Vis diffuse reflectance spectra and Fourier transform infrared. The results indicated that the catalyst consists of cubic-phase CdS and fluorite-phase CeO₂ structures, which formed a basic layered structure of sulfydryl kaolin after the CdS and CeO₂ were destroyed. The catalyst exhibited its highest photocatalytic activity for the degradation of crystal violet at a CeO₂:CdS molar ratio of 4:6 and mass ratio of sulfydryl kaolin to CeO₂-CdS of 1:3. It should be noted that the adsorption edge of the sulfydryl kaolin/CeO₂ was predicted to be 450 nm, whereas the optimum catalyst showed strong absorption at 550 nm. The crystal violet was decolorized by 95.1% within 150 min under a 350 W Hernia lamp at an initial concentration of 10 mg/L in a 50mL solution in the presence of 0.1 g of the optimized catalyst. The optimized catalyst exhibited a good repeatability with a removal rate of the crystal violet as high as 90.4% after 5 cycles. The related mechanistic experiments indicated that crystal violet was eventually decomposed to form CO₂ and H₂O. Hydroxyl and superoxide radicals were identified as the primary and secondary active species, respectively, in the degradation of crystal violet.