Abstract: The research of hydrogen production from water decomposition and pollutant degradation using g-C₃N₄ as photocatalyst has been widely concerned, but how to prepare efficient, stable and good photothermal stability catalyst by a simple and easy method is the research hotspot and difficulty. A simple hydrothermal method was used to introduce more amino groups on the surface of g-C₃N₄. The influence of surface amination on the surface morphology of g-C₃N₄ was studied by SEM and TEM, and find that amination has a great influence on the morphology of edge position. XRD, FTIR, UV-vis, XPS analysis show that the surface amination reaction dose not damage the main structure of g-C₃N₄. Studies on photocatalytic water hydrogen production and rhodamine B (RhB) degradation performance show that the highest hydrogen production rate of g-C₃N₄ when treated with 15wt% ammonia (180.24 μmol·g⁻¹·h⁻¹), which is 1.46 times higher than that of g-C₃N₄ (123.04 μmol·g⁻¹·h⁻¹). At the same time, the photocatalytic degradation performance of RhB also reaches the optimum. The degradation rate of RhB is 98.12% in 90 min duration irradiation, which is 1.55 times higher than that of g-C₃N₄ (63.28%). Neither too high nor too low ammonia concentration can make the photocatalytic performance reach the optimum. The photoelectric performance test results show that the mechanism of the enhancement of photocatalytic performance after surface amination can be attributed to the fact that the amino group is an electron donor group. After excitation, the increase of amino content is conducive to the occurrence of photocatalytic reaction, and excessive amination leads to the destruction of the delocalized triazine ring structure, and the photocatalytic performance is greatly reduced.