The paper firstly examines the degradation mechanisms of membrane electrode assemblies and bipolar plates (mainly including the mechanical, thermal and chemical degradation of proton exchange membranes), platinum dissolution and carbon support corrosion within the catalyst layer, carbon corrosion in the gas diffusion layer as well as the sealing integrity and corrosion resistance of bipolar plates. Subsequently, current durability evaluation methodologies for individual components are reviewed in light of their respective degradation mechanisms. It is identified that existing evaluation approaches exhibit significant variations in test conditions, performance metrics and aging protocols, leading to challenges such as lack of standardized criteria, limited test coverage and poor correlation with real-world operating conditions. Finally, drawing upon the understanding of component-specific degradation behaviors and the state of the art in evaluation techniques, it is proposed that the development of a systematic, accelerated and operationally representative durability testing framework represents a critical direction for future research and industrial advancement.