To analyze the risk factors of hyperthermia after removal of drainage tubes in patients after neurosurgery. The clinical data of 146 patients after neurosurgery with indwelling drainage tubes admitted to the department of critical care medicine of Pecking University Third Hospital from January 2019 to July 2021 were analyzed retrospectively. The patients were divided into hyperthermia group (body temperature ≥ 39 centigrade) and non-hyperthermia group (body temperature < 39 centigrade) according to whether their body temperatures within 24 hours after removal of drainage tubes. General clinical data and outcomes of the two groups were collected, and different tendentious scores were matched with the hyperthermia group and non-hyperthermia group based on Glasgow coma score (GCS), respectively. After such matching, the clinical baseline characteristics [age, gender, admission diagnosis, major complications, acute physiology and chronic health evaluation II (APACHE II) at admission, GCS], number of days of drainage tubes retention, location of drainage tubes, microbial culture results before removal of drainage tubes, white blood cell (WBC) and neutrophil ratio (NEU%) before and after removal of drainage tubes as well as clinical outcomes of the cohort patients were analyzed. The primarily outcome was in-hospital mortality, and then the length of intensive care unit (ICU) stay. A total of 146 patients after neurosurgery were included, 28 of which developed hyperthermia after removal of drainage tubes. The GCS scores at admission in the hyperthermia group were significantly lower than that in the non-hyperthermia group, while the proportion of hypertension and diabetes in the hyperthermia group was significantly higher than that in the non-hyperthermia group. Based on GCS scores, the two groups, each of which included 28 patients, were matched with tendentious scores, and there was no significant difference in gender, age, GCS scores and the proportion of hypertension and diabetes between the two groups. The main disease for patients upon admission was cerebral hemorrhage (53.6%, 30/56). The proportion of indwelling ventricular drainage tube retention in the hyperthermia group was significantly higher than that in the non-hyperthermia group [32.1% (9/28) vs. 7.1% (2/28), P < 0.05], but there was no significant difference in the location of other drainage tubes between the two groups. The proportion of lumbar puncture in the hyperthermia group was also significantly higher than that in the non-hyperthermia group [25.0% (7/28) vs. 0 (0/28), P < 0.05]. Compared with the non-hyperthermia group, WBC [×109/L: 13.0 (9.5, 15.2) vs. 11.5 (8.8, 13.3)] of 1 day before removal of drainage tubes, NEU% [0.892 (0.826, 0.922) vs. 0.843 (0.809, 0.909)] after removal of drainage tubes and positive rate of drainage-fluid culture or drainage-tube-tip culture [7.1% (2/28) vs. 0% (0/28)] in the hyperthermia group increased, but there were not significant differences. There was no significant difference in the proportion of pulmonary, urinary system and blood flow infection before removal of drainage tubes in the two groups. In terms of primary outcomes, compared with the non-hyperthermia group, the length of ICU stay [days: 17.0 (8.0, 32.3) vs. 8.5 (1.0, 16.8), P < 0.05] in the hyperthermia group was significantly prolonged, and the in-hospital mortality [35.7% (10/28) vs. 10.7% (3/28), P < 0.05] in the hyperthermia group was obviously increased. The positive rate of carbapenem-resistant bacteria culture [32.1% (9/28) vs. 3.6% (1/28), P < 0.05] in the hyperthermia group during hospitalization was significantly higher than that in the non-hyperthermia group. Hyperthermia after removal of drainage tubes for patients after neurosurgery can significantly prolong the length of ICU stay and increase the in-hospital mortality, which may be related to the secondary infection caused by indwelling intracranial drainage tubes and the intracranial spread of bacteria caused by removal of drainage tubes, as well as the intracranial multidrug-resistant bacterial infection caused by the drainage tubes.