Highly efficient, earth-abundant, and low-cost photocatalysts are widely pursued for solar-driven hydrogen generation from water. Herein, we first report vanadium disulfide (VS2) with high hydrogen evolution reaction (HER) activity both in basal and edges to be the co-catalyst of graphitic carbon nitride (g-C3N4) for ultrahigh solar-driven hydrogen production. VS2-decorated g-C3N4 shows an impressing photocatalytic hydrogen evolution with a rate of 87.4 mu mol/h, 26 times higher than pristine g-C3N4. Our combined experimental and computational studies reveal that the excellent efficiency of the composite is attributed to: (1) effective electron-hole separation and electron transfer from g-C3N4 to VS2, resulting from the optimal band alignment between VS2 and g-C3N4 and metallic characteristic of VS2; (2) fast hydrogen generation on the surface due to the high surface area and excellent HER activity of VS2. Our findings demonstrate that VS2/g-C3N4 may be applicable in solar driven water splitting, and the design principle can be applied to search for novel photocatalysts.