A Z-scheme heterostructure, few-layer MoS2/Bi2MoO6, was synthesized and exhibited excellent photocatalytic activity in oxidation of organics and inactivation of bacteria in water under visible light. Layered MoS2 with a thickness of similar to 1 nm were successfully deposited on the surface of Bi2MoO6 hierarchical microspheres. Compared with the MoS2 bulk, the band gap of layered MoS2 is widened, which is in favor of the separation of photogenerated charge carriers. After the introduction of MoS2, the photocurrent density was greatly improved on Bi2MoO6 electrode under visible light. This indicates that the recombination of photogenerated h(+)/e(-) was effectively suppressed with the modification of MoS2 nanosheets. Correspondingly, the photocatalytic oxidation activity in both the decomposition of organics in water and the inactivation of bacteria was enhanced. Possible mechanisms were proposed and discussed. This work sheds a light on the importance of applying layered MoS2 to improve the oxidation activity of a photocatalyst under visible light.