The design and development of highly active, low-cost catalytic materials play a crucial role in the advancement of electrochemical catalytic technologies. Understanding the true correlation between the structural features of catalysts and their electrocatalytic performance is essential for guiding the rational design of more efficient catalysts. However, currently, most electrocatalysts undergo multiple dynamic reconstructions under operational conditions, involving changes in composition, structure, and morphology, which makes the process of designing effective catalysts heavily reliant on extensive trial-and-error experiments. Although various advanced in situ, real-time, and high spatiotemporal resolution characterization techniques have been developed to monitor the changes in catalysts during operation, there remains a significant discrepancy between the testing conditions of these techniques and the actual working environments of catalysts, leading to challenges in accurately understanding catalytic mechanisms and structure–performance relationships under realistic conditions. In response to this problem, the applicant will base their discussion on recent research achievements, focusing on the stability methods and mechanisms of electrocatalysts composed of single metals, alloys, and compounds. The proposed approach emphasizes starting from the source—namely, the initial design and synthesis—to develop new strategies for preparing catalysts with high activity and stability. This approach aims to establish a deeper understanding of the structure–performance relationship and to provide innovative ideas for the rational design and synthesis of highly efficient catalysts, ultimately advancing the field of electrochemical catalysis and facilitating the development of practical, cost-effective catalytic systems for energy conversion and storage applications.