The invention discloses the application of cerebroside B which is extracted and prepared from termitomyces in preparing a medicine for treating ischemic brain injury. The application proves that a cerebroside compound has obvious treatment function on ischemic brain injury through pharmacology experiments, can reduce the cerebral infarction area which is caused by cerebral ischemia and relieve the cerebral edema through a blood-brain barrier, reduce the death of nerve cells, and simultaneously promote recovery of movement and cognitive functions after cerebral apoplexy, so the death rate of the cerebral apoplexy is reduced. The application develops the new medicine application of the cerebroside compound, and new therapeutic drugs are provided for treating diseases of the cerebral apoplexy.