Objective To analyze the clinical data of patients with chronic suppurative otitis media undergoing endoscopic type I tympanoplasty, and to explore the influence of Eustachian tube（ET） function on their hearing. Methods A total of 42 patients diagnosed with chronic purulent otitis media were collected, and the patients were divided into the study group with 25 cases of eustachian tube dysfunction and the control group with 17 cases of normal eustachian tube function, and the changes of hearing before and after surgery were compared and analyzed by combining the sound conduction anti-positive and negative pressure balance test and the Eustachian tube dysfunction (ETD) scoring scale（ETDQ-7）. Results The average hearing threshold of air conduction and bone conduction in the study group were higher than those in the control group, and the difference was not statistically significant (P <0.05). There was no significant difference between the 4000Hz air-conduction hearing threshold in the study group and the control group (P >0.05), and the 8000Hz air-conduction hearing threshold in the study group was lower than that in the control group (P <0.05). Conclusion Good eustachian tube function does not increase the degree of improvement of the average hearing of patients with chronic suppurative otitis media, but it is beneficial to the recovery of high-frequency hearing after surgery.