Objective To discuss the clinical value of Dimethicone power applied under endoscopy in examination of upper gastrointestinal tract. Methods 800 patients who received common endoscopy examination from Nov. 2014 to Nov. 2015 were recruited into the study and randomly divided into two groups: experimental group and control group. Fifteen minutes before the examination, the experimental group took Dimethicone power 5 g and 30 ml pure water. At the same time, the control group took 30 ml pure water only. According to the clarity of the endoscopic field of vision, the examination results were classified into 4 levels (A, B, C, D), and the inspect time of each patient was recorded. Results In experimental group, endoscopic vision was significantly higher than control group (P < 0.05), and the inspect time was significantly shorter than control group (P < 0.05). Conclusion Dimethicone power can significantly improve the clarity of the endoscopic field of vision and alleviate the suffering of patients with shorter inspect time, which can be used as an adjuvant before routine endoscopy examination.