〔Abstract〕 Objective To explore the application effect of the modified catheterization method in the drilling and drainage of chronic subdural hematoma. Methods 60 patients with chronic subdural hematoma admitted to Zhongshan Dongfeng People’s Hospital from March 2019 to July 2020 were selected and all underwent drilling and drainage treatment. They were divided into a control group and an observation group by computer randomization, 30 cases each. The control group used the traditional singlehole drilling flush drainage method, and the observation group used the modified catheterization method. The surgical treatment, intracranial gas, infection occurrence and drainage of the two groups were compared, and statistics were obtained 3 months after the operation. Results The hospitalization time of the observation group was shorter than that of the control group, and the difference was statistically significant (P < 0.05). There was no statistically significant difference in the operation time and intraoperative blood loss between the two groups (P > 0.05); The incidence of intracranial gas and intracranial infection in the observation group were lower than those in the control group, and the differences were statistically significant (P < 0.05); The rate of patency of the drainage tube of the observation group was higher than that of the control group at 1 and 2 days after operation, the difference was statistically significant (P < 0.05); 3 months after the operation, the recurrence rate of the observation group was 6.67% (2/30), lower than 26.67% (8/30) of the control group, the difference was statistically significant (P < 0.05). Conclusion The application of modified catheterization in the drilling and drainage of chronic subdural hematoma can effectively reduce intracranial gas and infection events, maintain the drainage tube unobstructed, shorten the patient's postoperative recovery time, and reduce the risk of recurrence.