The role of lumbar large pool drainage is to treat headaches caused by intracranial infections and subarachnoid hemorrhage.1. Intracranial infections. Due to intracranial infection, there are persistent bacteria in the patient’s skull, leading to complications such as nausea, vomiting, impaired consciousness, cervical rigidity, etc. Damage to the brain parenchyma can occur in severe cases. Through lumbar large pool drainage, the infected cerebrospinal fluid can be replaced outside the body, thus alleviating and achieving the purpose of treating patients.2. Subarachnoid hemorrhage. Subarachnoid hemorrhage can easily cause severe headache due to the stimulation of arachnoid membrane by blood, and through lumbar pool drainage, the bloody cerebrospinal fluid can be replaced to the outside of the body, so as to reduce the pain.