Developing highly efficient hydrogen evolution cocatalysts is of great significance for semiconductor photocatalysts toward the large-scale conversion of solar light energy into clean hydrogen fuel. Herein, a novel Ni/VN hetero-nanosheets is reported for the first time, as precious metal-free co-catalyst for g-C3N4, and the electronic coupling between Ni and VN greatly promotes the photocatalytic hydrogen production activity of g-C3N4 nanosheet (CNNS) under visible-light irradiation. As expected, CNNS with 3 wt% Ni/VN (CNNS/Ni/VN) exhibits excellent photocatalytic activity with hydrogen production rates are as high as 417.1 μmol h−1g−1. In addition, CNNS/Ni/VN has excellent cyclic hydrogen production stability for 24 h. This excellent performance is attributed to the strong electron coupling between Ni and VN. Therefore, the Ni/VN cocatalysts will open a newfangled way for powerful solar-fuel production.