After craniotomy, the period of intracranial infection is usually 3-4 days after the craniotomy. If there is intracranial infection, the body temperature will gradually show a rising trend 3-4 days after craniotomy, and often the temperature will exceed 38.5 degrees Celsius, and the application of general antipyretic drugs can not completely reduce it to normal, and it will happen repeatedly, not easy to fall. There are also a series of manifestations such as headache, nausea and vomiting, neck stiffness, and even convulsions and coma in some cases. If intracranial infection is highly suspected, early lumbar puncture testing must be performed. Based on the results of the lumbar puncture laboratory tests of cerebrospinal fluid, it is decided whether the infection is intracranial and what antibiotics should be applied for treatment.