Piezoelectric catalysis has shown great potential for application in green chemistry due to its “clean” properties. By applying external mechanical force, this method can induce rapid charge transfer, providing an important reaction pathway for carbon neutrality and carbon peaking. Carbon nitride (C3N5)-based catalysts, as a novel material, have received widespread attention for their synthesis and application in the piezoelectric catalytic degradation of organic compounds. This review summarizes the latest research progress of C3N5-based catalysts, covering their applications in environmental governance and resource utilization, including the removal of organic pollutants in water. We focused on the synthesis strategy, characterization methods, and application progress of C3N5-based catalysts in the degradation of organic pollutants. The quantitative results show that some C3N5-based catalysts had removal efficiencies of over 85% in the treatment of specific pollutants. In addition, this article also discusses the piezoelectric effect and its degradation mechanism, providing direction for future research. Finally, the application prospects and potential development directions of C3N5-based catalysts in environmental governance are discussed.