BACKGROUND This study explores the clinical efficacy of endoscopic mastoidectomy revision surgery in treating discharging surgical cavities, analyzes the causes of discharging surgical cavities, and summarizes the key technical points. MATERIAL AND METHODS A retrospective analysis was performed on the clinical data of 47 patients who underwent endoscopic revision mastoidectomy in the Department of Otolaryngology, Nanshan People's Hospital of Shenzhen from January 2020 to December 2024. Preoperative examinations included temporal bone computed tomography and pure-tone audiometry. Surgery was performed under general anesthesia with continuous irrigating mode of the endoscope. Operation time, complications, dry ear time, dry ear rate, and hearing improvement were recorded, with a follow-up of 6 to 18 months. RESULTS The average age of the 47 patients was 38.74±11.28 years, with 53.19% male and 46.81% female patients. The main causes included insufficient opening of the surgical cavity, recurrence of cholesteatoma, poor drainage of the surgical cavity, and lesions at the tympanic orifice of the eustachian tube. Average operation time was 125.17±45.05 minutes, and the average dry ear time was 75.16±31.44 days. Postoperative dry ear rate was 100%, with no serious complications. Hearing was significantly improved, and there was no recurrence of cholesteatoma during the follow-up period. CONCLUSIONS Endoscopic revision mastoidectomy can effectively treat discharging mastoid cavity and improve the dry ear rate and hearing by thoroughly removing lesions and optimizing cavity anatomy. Techniques such as continuous irrigating mode and concentrated growth factor combined with hydroxyapatite obliteration help improve surgical safety and prognosis.