A set of novel Ag2S/BiVO4 composites with different Ag2S content have been fabricated through a hydrothermal method and subsequent precipitation procedure using 3-mercaptopropionic acid (MPA) as a surface functionalization agent. The photocatalytic performance of the samples for RhB degradation was evaluated under visible-light irradiation. The results show that the Ag2S/BiVO4 composites present a much better photocatalytic activity than bare Ag2S and BiVO4. After 100 min visible-light irradiation, a maximum degradation rate of up to 95.1% has been obtained for Ag2S/BiVO4 composite containing 0.5 wt% Ag2S. The reason for improvement in visible-light-driven photocatalytic performance could be due to the increased visible-light absorption as well as the successful construction of suitable heterojunction structure between Ag2S and BiVO4. The active species trapping experiments confirm that .O-2(-) and h(+) are the primary active oxidizing species during the photo degradation process. A possible and reasonable photocatalytic degradation mechanism for the Ag2S/BiVO4 composites has been proposed.