Objective To explore the effect of exercise intervention on the quality of bowel preparation in children undergoing colonoscopy, and to provide a reference for improving the effect of bowel preparation in children with colonoscopy. Methods A total of 166 children who underwent colonoscopy in gastroenterology department from July 2021 to June 2022 were selected as the research objects.According to the order of admission time, they were divided into the control group （80 cases） and the intervention group （86 cases）.The control group received routine bowel preparation, while the intervention group received exercise intervention on the basis of routine bowel preparation.The compliance of bowel preparation, qualified rate of bowel cleanliness and incidence of adverse reactions were compared between the two groups. Results The compliance of bowel preparation and qualified rate of bowel cleanliness in the intervention group were higher than those in the control group, and the incidence of abdominal distension/abdominal pain was significantly lower than that in the control group (all P＜0.05). Conclusion Exercise intervention can improve children and their parents′ compliance with bowel preparation, effectively ensure the cleanliness of children′s bowel preparation, thus improve the quality of bowel preparation for children undergoing colonoscopy.