The invention discloses a functional food for assisting in repairing digestive tract mucous membranes after chemotherapy. The functional food comprises galactooligosaccharide, stachyose, mannan oligosaccharide, glutamine, vitamin A, vitamin D3, vitamin E, vitamin B1, vitamin B2, vitamin B6, vitamin B12, vitamin C, nicotinic acid, folic acid, pantothenic acid, biotin, choline, inositol, calcium, potassium, magnesium, iron, zinc, iodine, selenium, copper, manganese, DHA, EPA, omega-3 and phosphatidylserine. The functional food can effectively repair digestive tract barriers, improve the immunityof tumor patients and effectively reduce the side effects of chemotherapeutic drugs on digestive tracts after chemotherapy.