As the increasing demand for ammonia in other industries such as energy, the ammonia production now available can no longer meet the needs of industrial production, and the existing Haber-Bosch process for the production of NH₃ will cause harm to the atmospheric environment. Therefore, there is an urgent need to find a new method that is compatible with or can replace the existing ammonia production process. Nitrate wastewater contains a large amount of nitrogen, and NH₃ is one of the nitrate reduction products, the reduction of nitrate into ammonia can not only reduce the environmental pollution of nitrate nitrogen, but also alleviate the industrial demand for ammonia, nitrate wastewater treatment methods are generally physical, chemical and biological, but there are shortcomings of long cycle time and high cost. The electrocatalytic method is convenient, safe and can catalyze the synthesis of NH₃ at room temperature and pressure, which makes the electrocatalytic synthesis of NH₃ become a hot research topic in recent years. In this experiment, 3-amino-1,2,4-triazole was loaded into alumina crucible and used as the precursor to synthesize C₃N₅ by pyrolysis method in Muffle furnace, and then Cu-C₃N₅ was synthesized under calcination conditions by modulating the ratio of copper elements, which resulted in a series of C₃N₅-based catalysts with differences in material morphology, crystal conformation, and chemical valence state, including five catalysts of different proportions were synthesized. These catalysts were tested, then their electrochemical performance and electrocatalytic reduction of nitrate to produce ammonia performance were evaluated, and it was found that the ammonia yield and Faraday efficiency could reach 0.541 mmol•h⁻¹•mg_cat⁻¹ and 87.79% by 1 h electrolysis experiments in a mixed electrolyte solution of 0.1 mol/L KOH＋0.1 mol/L KNO₃, which are much higher than that of C₃N₅, and the catalyst has good activity and stability in cyclic and long time experiments, indicating that it has some research value in the field of electrocatalytic nitrate.