Objective To investigate the effect of intravenous glutamine (Gln) on intestinal mucosal barrier function in colon patients undergone surgery. Methods According to the number of patient hospital mantissa odd and even difference, a total of 98 patients undergoing colon cancer surgery in the First Hospital of Shanxi Medical University from May 2016 to August 2017 were selected and divided into treatment group (Ala-Gln) 46 cases (added alanyl glutamine injection) and control group of 52 patients (blank control) by observing the two groups of patients's serum levels of diamine oxidase (DAO), D-lactate (D-lactate), endotoxin Changes,in order to explore the two groups of patients with intestinal mucosal barrier function changes. Results The levels of D-lactic acid, DAO and endotoxin in the two groups before surgery and on the first day after operation were not statistically significant (P>0.05). On the 3rd, 5th and 7th day after operation in the treatment group, Serum D-lactate, DAO and endotoxin levels were significantly lower than the control group (P<0.05). The differences of D-lactate, DAO and endotoxin levels on day 3, 5, and 7 after operation with those on the first postoperative day were statistically significant, and the difference between the treatment group was significantly higher than that of the control group (P<0.05). Conclusions Surgery can cause further damage of intestinal mucosal barrier function in patients with colon cancer. Postoperative intravenous glutamine can significantly improve the intestinal mucosal barrier function, which is beneficial to the recovery of postoperative intestinal mucosal barrier function in patients with colon cancer.