In recent years, the threat of diabetes to human health is getting worse and worse, and the treatment and rehabilitation of diabetes have drawn great public attention. As an important vehicle of managing blood sugar, diet control is favored because of few side effects. Highland barley is rich in nutrients, including polyphenol, β-glucan, and other bioactive ingredients. Moreover, the experimental results in vivo and in vitro have fully proved that it has various health benefits, especially in reducing the rising level of blood glucose. Although the researches on the hypoglycemic mechanism of highland barley have increased year by year, mainly focused on the impact of a single component on blood glucose, and there is still a lack of comments systematically explaining the overall involvement of highland barley in glycemic management. Therefore, with the research literature mainly of the recent three years reviewed, this paper summarized the hypoglycemic effect of highland barley from the perspectives of nutritional composition and bioactive components (polyphenol, β-glucan, etc.), and analyzed the utilization of highland barley hypoglycemic food, in order to provide some theoretical references for further exploring the hypoglycemic mechanism of highland barley and developing highland barley functional food.