Abstract: Objective To investigate the effects of administration of dimethicone via different routes on gastroscopy. Methods A total of 180 patients who were admitted into Digestive Endoscopy Center, the Fourth Affiliated Hospital of Anhui Medical University from March to August 2018 were selected. They were divided into three group, according to their corresponding treatment (n=60): a control group who was orally given lidocaine mucilage, an oral administration group who was orally taken dimethicone powder, and a spray group who was sprayed with dimethicone dilute by forceps. Their length of gastroscopy, the clarity of gastric mucosa vision, and lesion detection rate were evaluated. Results Remarkable decreases were found as to the length of gastroscopy in the oral group (5.34±1.36) min and in the spray group (5.83±1.92) min, compared with that in the control group (6.78±1.91) min (P<0.05). Both the spray and oral groups presented significantly improved clarity of gastric mucosa vision (P<0.05), where markedly good clarity of gastric mucosa vision was found in the spray group in comparison with the oral group (P<0.05). The detection rate of gastric mucosal lesions was 63.33% for the spray group, which was significantly higher than those in the oral group (31.67%) and the control group (18.33%)(P<0.05). Conclusions During gastroscopy, oral administration of dimethicone and spraying dimethicone diluent by forceps can improve the efficacy of removing bubbles and improve the clarity of vision under endoscopy. Spraying dimethicone powder through forceps can better detect lesions and improve the diagnosis rate of lesions.