The main solutions for lactose intolerance are dietary modification, probiotic supplementation, and lactase enzyme. Lactose intolerance is mainly due to some people’s intestinal secretion of lactase enzyme is insufficient or the activity of the enzyme decreases, resulting in the intake of breast milk, milk or food lactose can not be broken down by the enzyme lactase, digestion, resulting in the fermentation of lactose in the intestinal tract to produce gas and lactic acid, lactose and lactic acid will lead to intestinal permeability increases caused by diarrhea, abdominal distension, abdominal pain and other symptoms. Lactose-intolerant people should avoid eating foods containing lactose or eating foods rich in carbohydrates in their daily diet. Instead of lactose, foods containing maltose and glucose can be eaten to replenish the body’s nutritional needs. When the diarrhea caused by lactose intolerance stops, the intake of lactose can be gradually increased to increase the body’s tolerance to lactose. If it is secondary lactose intolerance people can be under the guidance of the doctor to supplement probiotics, lactase, such as lactobacillus, bacillus, E. coli, lactase, etc., can stimulate the secretion of lactase by intestinal epithelial cells to alleviate the symptoms of lactose intolerance. If people with lactose intolerance experience diarrhea for a long period of time without relief, they should go to the hospital for relevant examinations in time.