Abstract: Objective To analyze the effects of dexmedetomidine pretreatment on postoperative oxidative stress and intestinal barrier function in elderly patients undergoing laparoscopic surgery. Methods Seventy-four patients who underwent laparoscopic surgery at Xixi Hospital from January to December 2018 were divided into dexmedetomidine group(37 cases) and control group(37 cases) according to whether they received dexmedetomidine pretreatment. The general data, heart rate and blood pressure before anesthesia, 1 min, 5 min and 30 min after anesthesia were compared. The oxidative stress and intestinal barrier function were compared 24 h after surgery. Results There were no significant differences in blood pressure, heart rate, adverse reactions, preoperative oxidative stress, and intestinal barrier function between the two groups(all P>0.05). The sedative effect and the recovery time after stopping the drug of the dexmedetomidine group were significantly lower than those of the control group(all P<0.05). The Ramsay scores at 1 h and 2 h after operation of the dexmedetomidine group were significantly higher than those of the control group(all P<0.05). The dose of fentanyl of the dexmedetomidine group was significantly lower than that of the control group(P=0.001). The MDA of the two groups was increased, and the SOD, GSH-Px, TAS, I-FABP, endotoxin, DAO and D-Lactic acid was decreased after operation. The MDA, I-FABP, endotoxin, DAO and D-lactic acid of the dexmedetomidine group were significantly lower than those of the control group(all P<0.05), and the SOD, TAS, GSH-Px were significantly higher than those of the control group(all P<0.05). Conclusion Pretreatment with dexmedetomidine can effectively shorten the onset of sedation and recovery time after surgery, which can effectively improve the postoperative intestinal damage and reduce the occurrence of oxidative stress.