Optic nerve compression is a common symptom of craniopharyngioma, which is characterized by changes in visual acuity, visual field and fundus changes. The suprasellar tumor has different compression sites due to its irregular growth direction, so the visual field defect varies greatly, which can be quadrant defect, hemianopia, dark spot and so on. The tumor can cause visual field defect by compressing the optic cross, and the common one is temporal hemianopia, such as bilateral temporal lower quadrant hemianopia, suggesting that the compression is from top to bottom, and the degree of damage of both sides may not be the same. If the tumor compresses only one side of the optic tract, it will produce isotropic hemianopia. If the tumor severely compresses the optic cross, it may cause primary optic nerve atrophy; if the tumor invades the third ventricle and causes hydrocephalus and increased intracranial pressure, it may produce secondary optic nerve atrophy. Oculomotor nerve may be involved, resulting in diplopia and other symptoms. 2. Intersaddle type tumor compresses the optic cross from below to upward, producing visual field defect same as pituitary tumor, and vision loss is related to optic nerve atrophy. Sometimes it can cause sudden blindness due to bleeding infarction at the optic cross and blood circulation obstruction. In patients with primary optic nerve atrophy, optic disc edema rarely occurs again. Foster-Kennedy syndrome can occur when the tumor grows to one side. In children, early visual field defects are often unnoticed until severe visual impairment is detected.