As an important cereal crop, barley occupies an important position in feed production and food processing. Proteins in barley grains have significant effects on the beer brewing process and beer quality, especially in terms of its foaming capacity and turbidity. However, little research has been conducted on the important proteins in barley such as hordeins and heat-stable proteins (protein Z and lipid transfer proteins). Information on their structure is lacking, and the development of their functions is still in its early stages. This review paper focuses on the structure, functional properties and application of important proteins in barley, and outlines their roles and changes in beer brewing with the aim of providing theoretical references for their processing and utilization.