To explore the effects of simethicone combined with compound polyethylene glycol for bowel cleaning on the detection rate of intestinal polyps. A total of 300 patients undergoing colonoscopy from May to July 2020 were randomly divided into group A and B. Patients in group A only used 2 packets of compound polyethylene glycol electrolyte powder for bowel cleaning. Patients in group B took simethicone combined with compound polyethylene glycol for intestinal cleaning. The time, method and dosage of compound polyethylene glycol were the same as those of group A. Intestinal cleanliness, intestinal defoaming degree, intestinal polyp detection rate and incidence of adverse reactions in group A and B were compared respectively. The scores of intestinal cleaning, the rate of intestinal foam removal and the detection rate of large and small polyps in group B were higher than those in group A. There was no significant difference in the incidence of short-term adverse reactions between the two groups. However, the incidence of postoperative abdominal distension in group B was significantly reduced. Simethicone combined with compound polyethylene glycol for bowel cleaning can significantly improve the degree of intestinal cleaning and improve postoperative abdominal distension. It has obvious effects on improving the detection date of intestinal polyps and preventing the occurrence of certain intestinal tumors. The method is simple, feasible and economical, which is worth promoting.