Phytoglycogen (PG), a carbohydrate polymer extracted from sugar-containing mutant seeds of plants, is a natural dendrimer-like glucan nanoparticle with high safety. The highly branched structure of phytoglycogen that is externally compact and internally loose provides it with high water retention, low viscosity, good dispersion stability, strong antioxidant and antibacterial activity, film-forming capacity, and excellent load capacity. Thus, in recent years, phytoglycogen has gradually become one of the research hotspots. However, there are few reports on the extraction, structural analysis, and comprehensive utilization of phytoglycogen so far. Therefore, this review focuses on the structure and properties of phytoglycogen, discusses the latest extraction methods for phytoglycogen, summarizes its application in foods, and provides an outlook on future research prospects, aiming to provide a theoretical basis for expanding the application of phytoglycogen.