The most common symptom of subarachnoid hemorrhage due to trauma is headache, which may be combined with intracranial hypertension, vomiting, and optic papillomegaly. If the subarachnoid hemorrhage is large, it may lead to brain herniation, headache, vomiting, optic papillar edema, or even coma. If the subarachnoid hemorrhage causes brain herniation, there is a risk of respiratory and cardiac arrest. Therefore, once a subarachnoid hemorrhage is detected, it is important to identify the cause as soon as possible and intervene as soon as possible. If brain herniation occurs, emergency craniotomy with decompression of the bone flap or hemostasis after debridement is recommended.