OBJECTIVE To investigate the effect of sustained-release glucocorticoid stent on nasal mucosal eosinophil(Eos)%and nasal microbiota in patients undergoing eosinophilic chronic sinusitis with nasal polyps(ECRSwNP)surgery.METHODS A total of 104 patients with ECRSwNP admitted to Qianjiang Central Hospital from August 2020 to August 2022 were selected.The patients were randomly divided into an observation group and a control group,with 52 patients in each group.During nasal endoscopic surgery,slow-release glucocorticoid stents were implanted or not.The hospital stay,nasal ventilation recovery time,and total effective rate of treatment were compared between the two groups.The nasal mucosal Eos%and nasal microbiota were compared between the two groups before and one month after surgery.The Lund-Kennedy score of nasal endoscopy,SNOT-22 outcome tests,and visual analogue scale(VAS)scores were compared between the two groups before and three months after surgery.The intervention rate and frontal sinus patency rate at 3 months after surgery in two groups.RESULTS The hospitalization time and nasal ventilation recovery time of the observation group were significantly lower than those of the control group(P<0.05).The total effective rate of the observation group treatment was 92.31%(48/52),which was significantly higher than that of the control group 76.92%(40/52)(P<0.05).After surgery,the Eos%of the nasal mucosa in both groups significantly decreased compared to before surgery(P<0.05),and the observation group was lower than the control group(P<0.05).There was no statistically significant difference in Shannon index and Chaol index between the two groups before surgery(P>0.05);The Shannon index in the control group decreased significantly after surgery(P<0.05),while the Chaol index increased significantly after surgery(P<0.05);There was no significant difference in postoperative Shannon index and Chaol index between the observation group and preoperative group(P>0.05).After surgery,the Lund-Kennedy score,SNOT-22 score,and VAS score in both groups were significantly lower than before(P<0.05),and the observation group was lower than the control group(P<0.05).The intervention rate of the observation group was significantly lower than that of the control group(P<0.05),and the frontal sinus patency rate was significantly higher than that of the control group(P<0.05).CONCLUSION The sustained-release glucocorticoid stent is beneficial for the epithelialization of the surgical cavity in ECRSwNP patients,reducing mucosal Eos%,improving clinical symptoms,ensuring smooth frontal sinus drainage,reducing postoperative intervention rates,and having no significant impact on nasal microbiota.