Arachnoid cysts of the greater occipital pool are a relatively common disease and are benign cysts. The causes of the disease are more varied and the condition is more complex. Many patients are affected by the lack of obvious clinical signs and symptoms at first, and the severity is judged by the size and location of the cyst. If the cyst is too large, increased intracranial pressure can occur, leading to dizziness, nausea, vomiting, impaired consciousness, and even coma. Cysts close to the aqueduct or the IVth ventricle can also cause cerebral fluid obstruction, cerebellar ataxia, and severe headache. If it causes obvious clinical symptoms, surgery should be considered. After removal of the cyst, the healing process is relatively good, and the stitches can usually be removed in about 7 days after surgery and the symptoms basically disappear. Arachnoid cysts in the greater occipital pool may also be caused by congenital developmental abnormalities. If it is congenital, medication is usually ineffective. If the cyst is small and there are no symptoms such as headache, dizziness, nausea, vomiting, or impaired consciousness. It can be temporarily left untreated. If the cyst is large and symptoms of pressure such as headache occur, surgical treatment should be taken immediately to remove the cyst. In conclusion, arachnoid cyst in the occipital pool is a relatively common intracranial arachnoid cyst, which is a benign lesion and does not belong to a tumor.