Cold plasma technology enables atomic-level etching, surface peeling, and component reconstruction of material surfaces at near-room temperature. This capability effectively addresses the limitations of conventional high-temperature and wet chemical methods, which often fail to accurately construct and preserve highly active metastable defects. Thus, cold plasma has emerged as a key approach for developing high-performance, defect-rich electrocatalytic materials and enhancing the efficiency of electrochemical energy conversion. In this review, we summarize recent advances in plasma-assisted synthesis of defect-rich electrocatalysts. Firstly, the physical principles and advantages of low-temperature green synthesis were outlined. Then, we analyze the microscopic mechanisms underlying defect generation, such as vacancies, heteroatom doping and single-atom sites, through strategies including etching, doping, and redox reactions. Thirdly, the application and performance regulation mechanisms of these strategies in typical material systems and key electrocatalytic reactions were discussed. Finally, the potential future research directions, challenges, and development opportunities of cold plasma technology in electrochemical applications were summarized.