A Ni- and Co- sulfide co-doped g-C₃N₄ photocatalyst (g-C₃N₄/Ni_xCo_1−xS₂) was prepared by hydrothermal method and this photocatalyst, namely, g-C₃N₄/Ni_xCo_1−xS₂ shown excellent photocatalytic properties due to the special structure of Ni-Co-S with boundary different exposure to active site of transition metal-metal (Ni-Co) active planes. With the introduction of Co atoms, the H₂ production amount reached the maximum about 400.81 μmol under continuous visible light irradiation for 4 hours based on the efficiently charge separation and greatly improved electron transfer resulted from the presence of sufficient active exposure at the boundary. The serial studies shown that the existence of Ni-Co-S structure over g-C₃N₄ active surface is the key factor of activity affections by means of several characterizations such as SEM, XRD, XPS diffuse reflectance etc. and the results of which were in good agreement with each other. A possible reaction mechanism over eosin Y-sensitized g-C₃N₄/Ni_xCo_1−xS₂ photocatalyst under visible light irradiation was proposed.