Hybrid materials of SnS2 nanoparticles on graphene sheets (GS) were prepared by a facile one-step hydrothermal procedure. The as-obtained samples were characterized by X-ray diffraction (XRD), Raman spectra, UV-vis diffuse reflectance spectra (DRS), Transmission electron microscopy (TEM), photoluminescence spectra (PL) and electrochemical equipment. The effects of GS on photoabsorption range, the apparent band gap, the separation efficiency of photogenerated electron-hole pairs, and concentration of hydroxyl radicals of SnS2 were researched. The as-samples exhibited an enhanced absorption in the visible region (lambda > 600 nm) with increasing the amount of graphene and the band gap was about to 2.11 eV. The photocatalytic activity of GS/SnS2 is consistent with the results of photocurrents and concentration of hydroxyl radicals and the best ratio of graphene to SnS2 is 1%. The graphene can effectively promote the separation of photo-induced carriers and thus strengthen the photocatalytic ability. Furthermore, excess graphenes will not favor the enhancement of photocatalytic activity.