The Z-Scheme Ag3PO4/Ag/g-C3N4 nanosheets composites are synthesised via simple annealing and anion-exchange precipitation method. The obtained samples are characterized by SEM, XRD, TEM, XPS, UV-Vis and PL, which imply that the Z-Scheme Ag3PO4/Ag/g-C3N4 structure has been prepared successfully. The photocatalytic activity of the as-prepared Ag3PO4/Ag/g-C3N4 nanosheets composites displays a remarkable enhancement after the Ag3PO4/Ag nanoparticles being introduced by the hydrogen production under visible light. Further, the Z-Scheme structure of the sample and the lamellar structure of the C3N4 are considered as the main reasons for the enhancement.