Objective: To explore the effect of postural change and different intervals of waiting for operation on deforming performance of Dimethicone powder in endoscopy. Methods: Four hundred patients who were scheduled to gastroscopy between March and May 2016 in Endoscopy Center, Department of Gastroenterology, Chongqing Cancer Hospital were randomly divided into four groups: group A (recumbent and interval for 15 min), group B (postural change and interval for 5 min), group C (postural change and interval for 10 min), and group D (postural change and interval for 15 min). The comparative effect of deforming performance of Dimethicone power based on postural change and different intervals for operation was evaluated through assessing mucosal vision clarity. Results: The mucosal vision clarities of patients scheduled to postural change in esophagus, fundus ventriculi, gastric angle and sinuses ventriculi were superior to that of patients scheduled to recumbent, with significant statistical difference (P<0.05). For patients scheduled to postural change, the mucosal vision clarities of interval for 10 min in fundus ventriculi, corpora ventriculi, and sinuses ventriculi were superior to that of patients scheduled to interval for 5 and 15 min, with significant statistical difference (P<0.05). Conclusion: It could obtain the best vision clarity by reversing body immediately after taking Dimethicone powder and starting gastroscopy 10 min later, deserved further clinical applications.