In the photocatalytic hydrogen production reaction, the introduction of cocatalyst to promote the rapid transfer of photogenerated electrons is an effective way to improve the photocatalytic activity. At present, the most efficient cocatalysts are mainly precious metals, greatly restricting the use of this method. In this study, influence of the close interface between non-noble metal cocatalyst CoN and g-C₃N₄ 0D/2D on the performance of photocatalytic hydrogen production was explored. The results showed that the support of non-noble metal cocatalyst CoN can effectively improve the photocatalytic hydrogen production of 2D g-C₃N₄, and the support amount also has an positive effect on its activity. The compact 0D/2D interface is favorable for the rapid transmission of photogenerated electrons. Photocatalytic efficiency of 10% CoN/2D g-C₃N₄ composite reached 403.6 μmol·g^-1·h^-1, 20 times of that of 2D g-C₃N₄ monomer, which was comparable to that of noble metal cocatalyst. As a hydrogen evolution cocatalyst, loaded CoN can significantly promote the charge transfer process, thus greatly improving the activity of photocatalytic hydrogen evolution.