Series of CdS/Ag2S composite photocatalysts with different Ag2S concentrations were prepared by the precipitation-grinding method. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, UVvisible spectroscopy, and photoluminescence spectroscopy. The catalyst particle size of CdS/Ag2S was proved to be smaller than the catalyst particle size of CdS. The reaction system was set under visible light irradiation to study the influence to the photocatalytic performance of CdS/Ag2S with different condentration of Ag2S. The CdS/Ag2S composite photocatalyst with the weight of 100% concentration of Ag2S showed the highest photocatalytic activity and the degradation of Rhodamine B was 71%.The presence of Ag2S also restrained the recombination rate of e-/h+ pairs.The photocatalytic activity of degradation of Rhodamine B was significantly improving.