Mung bean (Vigna radiata L.), known as a traditional soy food which has been used both as nutritional food and herbal medicine over 2000 years. Mung bean polysaccharide, as one of the main active substances of mung bean, has antioxidant, immunomodulatory, hypoglycemic and antibacterial biological activities, which makes it a hot spot for research. This paper reviews the research progress on the extraction methods, structure and biological activities of mung bean polysaccharides. Several commonly used methods for the extraction and purification of mung bean polysaccharides were compared, focusing on the structure and activity of mung bean polysaccharides and the relationship between them. This study can provide references for the subsequent research, production and application of mung bean polysaccharides, and provide a theoretical basis for further development and utilization of mung bean polysaccharides.