Abstract: As a key component of polymer electrolyte fuel cells, the proton exchange membrane (PEM) directly impacts cell performance. Expanding its operational temperature and humidity range is advantageous for simplifying fuel cell water and thermal management designs, thereby promoting miniaturization and cost reduction. In recent years, the development of polymer composite membranes based on natural clay has emerged as a crucial avenue for enhancing traditional PEM performance and broadening its applicability across varying environmental conditions. Natural clay minerals predominantly consist of hydrated layered silicate compounds, characterized by unique pore and layer structures at the nanoscale, endowing them with substantial specific surface area and surface effects. The abundance of hydroxyl groups on their surfaces and interlayers not only enhances the mechanical strength of composite membranes but also immobilizes mass transport media. Consequently, these materials facili-tate the creation of novel proton-conductive pathways within the composite membrane, thereby elevating membrane performance. We comprehensively review, from a nanoscale perspective, various categories of clay minerals, elucidating their structural and performance attributes. Furthermore, we provide a comprehensive summary and future prospects of research advancements in natural clay mineral-composite proton exchange membranes.