The invention discloses an extraction process and application of grifolan. The grifolan is obtained by adopting a method with the steps of water extraction, alkaline extraction, ultrafiltration and alcohol precipitation; it is discovered that the grifolan can promote gastric mucosa epithelial cells to proliferate and migrate to a gastric mucosa wound area by up-regulating mRNA and protein expression level of TFF2 and protein expression level of EGF and down-regulating mRNA and protein expression level of TGF-beta1; thus the aim of promoting gastric mucosa healing and plerosis is achieved, and a basis is provided for developing and using grifola frondosa and overcoming gastric mucosa wounds and chronic gastritis.