The GES-1 cell injury model was induced by indomethacin to study the protective effect of polysaccharides and fruiting body polysaccharides of Hericium erinaceus on gastric mucosa. The extraction process of crude polysaccharides from Hericium erinaceus was optimized by water extraction and alcohol precipitation extraction method， and the difference of polysaccharides on gastric mucosa protection before and after purification was explored at the cellular level. Studies have shown that the crude polysaccharides of the mycelium of Hericium erinaceus and the crude polysaccharides of the fruiting bodies have obvious proliferative effects on GES-1 cells， and can significantly improve the survival rate of damaged GES-1 cells. The optimum conditions for the purification of crude polysaccharides from Hericium erinaceus were as follows： the ratio of solid to liquid was 1 ∶ 15， the extraction temperature was 80 ℃， and the extraction time was 2 h. Under these conditions， the purity of mycelium polysaccharide increased from 40% to 50%， the purity of fruiting body polysaccharide increased from 35% to 42%， and the survival rate of damaged GES-1 cells also increased significantly. The results indicated that the mycelium polysaccharides and fruiting body polysaccharides from Hericium erinaceus have good protective effects on gastric mucosa.