The incidence rate of traumatic brain injury （TBI） has been increasing year by year. The important challenges of TBI include secondary cerebral edema， changes in cerebrospinal fluid circulation dynamics， intracranial hypertension， and even encephalocele due to brain swelling. Consequently， it is of particular importance to explore an effective treatment method for TBI. There are still controversies over cerebrospinal fluid drainage in patients with severe TBI. Studies have shown that external lumbar drainage of cerebrospinal fluid can significantly reduce intracranial pressure and may play a key role in the treatment of intracranial hypertension due to TBI. .