Firstly, there is a history of head trauma, and after the injury, hemorrhagic bruises around the orbit, postauricular mastoid, posterior occipital subcutaneous, posterior pharyngeal mucosa or conjunctiva of the eye gradually appear; it may be accompanied by bleeding from the ear, nose, oropharynx and/or cerebrospinal fluid ear leakage, nasal leakage (clear water-like fluid from the ear and nose); there may be symptoms of cranial nerve injury. Skull base fractures are often linear fractures, and most of the skull base films cannot show the fracture line, so the diagnosis mainly depends on clinical manifestations. Treatment of skull base fracture: 1. apply antibiotics to prevent intracranial infection; 2. keep the external auditory canal and nasal cavity clean, forbid stuffing and flushing; 3. avoid lumbar puncture to avoid retrograde intracranial infection; 4. lie still, take a high head position, avoid various factors that cause increased pressure in the nasal cavity, such as coughing and sneezing; 5. cerebrospinal fluid leakage usually stops on its own 3-7 days after injury, if it does not heal within 1 month, consider If it does not heal within 1 month, cerebrospinal fluid leak repair can be considered. In addition, the combined occurrence of brain and blood vessel injury should be dealt with.