Tea is a natural beverage produced from fresh young leaves or buds of evergreen shrubs or trees in the Theaceae family through specific processing techniques, and it is now recognized as the most widely consumed plant-derived beverage worldwide. Tea polysaccharide (TPS) is one of the main active ingredients in tea, and is a polymer complex formed by the polymerization of multiple monosaccharides via glycosidic bonding. TPS has been found to exhibit multiple biological functions, including antioxidant and anti-inflammatory activities, regulation of lipid metabolism, and modulation of gut microbiota, with a close structure-activity relationship between its bioactivity and structural characteristics. Therefore, TPS is currently a key focus of tea development and applied research. Recent studies have shown that TPS can ameliorate liver injury through various mechanisms, including antioxidant activity, anti-inflammatory effects, regulation of lipid metabolism, and modulation of gut microbiota, with significant protective effects against both alcoholic and non-alcoholic fatty liver diseases. This paper reviews recent advances in domestic and international research on the extraction and purification of various TPS, their structural characteristics, and their hepatoprotective effects. Additionally, the paper summarizes the various pathways by which TPS improve liver injury, including alleviating oxidative stress, modulating the immune-inflammatory axis, and regulating lipid metabolism and gut microbiota. This study aimed to provide theoretical support and a practical foundation for the in-depth research on TPS and their innovative applications in the food industry.