Boosting the photo-induced charge separation on the interface of semiconductor photocatalyst still is an enduring challenge in photocatalytic water splitting for hydrogen production. Herein, 0D/2D CoS/g-C3N4 heterostucture was designed and constructed via a facile and green solvothermal synthesis, wherein the CoS nanoparticles were dispersedly anchored on the surface of g-C3N4 nanosheets. The morphology, microstructure, component of g-C3N4 and CoS/g-C3N4 samples were detailedly characterized by a sequence of physical and chemical characterizations. The thus-designed CoS/g-C3N4 photocatalysts manifest the enhanced photocatalytic performance for hydrogen production relative to the pristine g-C3N4. The optimized CoS/g-C3N4 photocatalyst gives the H2 production rate of 532 μmol g−1 h−1, which is about 44 times higher than that of the pristine g-C3N4. The photoelectrochemical measurements prove that its promotion is mainly attributed to the reinforced interface charge separation and transfer and the lower overpotential. Furthermore, the photoluminescence decay data of g-C3N4 and CoS/g-C3N4 photocatalysts clearly demonstrates the crucial role of CoS cocatalyst, which can prolong the charge lifetime of photocatalyst benefiting to the photocatalytic reaction process. This work provides a promising counterpart to realize the interface charge separation and transport in heterogeneous photocatalysis.