Abstract: Objective: To explore the effect of psychological intervention on anxiety in obese patients during colonoscopy. Methods: This study is a prospective, single-blind, randomized controlled experiment.We selected obese patients undergoing gastroscopy, and randomly divided patients into psychological intervention group (group T) and routine monitoring group (group C), with 42 patients in each group. All participants used routine health education during the examination, group T provided comprehensive psychological intervention.The State-Trait Anxiety Inventory was used to assess anxiety at 3 days, 30min and 30min before surgery.And recorded hemodynamic changes, time of examination, endoscopist satisfaction, patient comfort, drug dosage and adverse reactions during the examination(Intraoperative hypoxemia、 hypotension、bradycardia、postoperative nausea and vomiting、dizziness). Results: Compared with Group C, STAI score was significantly lower (P 0.05), And in the two groups of patients, Relative to the trait-anxiety level, A much greater decline in state anxiety; More stable hemodynamic changes in the T group, Blood pressure and heart rate during the examination were lower than that in group C (P 0.01); The examination time of group T was significantly shorter than that of group C (P 0.01); In the T group, endoscopic physician satisfaction and patient comfort were higher than that in the control group (P 0.01); The additional dose of drug in group T was lower than that in group C (P 0.01); The incidence of nausea, vomiting, and postoperative dizziness in Group T was less than that in Group C (P 0.01), The rates of hypotension, bradycardia, and hypoxemia were lower than those in Group C. However, the difference was not significant (P 0.05). Conclusion: Psychological intervention can improve the anxiety during gastroscopy, reduce the adverse reactions and improve the experience of gastroscopy.