When rectal cancer spreads to brain in advanced stage, headache, vomiting and other clinical manifestations may appear. Rectal cancer is a common malignant tumor, which can be caused by heredity, gene mutation and other factors. When the disease develops to the late stage, distant metastasis can occur, such as brain metastasis, at this time, due to the compression of the tumor, it can lead to intracranial hypertension, which can be specifically manifested as severe and persistent headache, projectile vomiting and other symptoms. In addition, specific manifestations may appear according to different metastatic sites, such as epilepsy, personality change and other mental symptoms in brain metastasis; cerebellar metastasis leads to unsteady gait, loss of balance, etc.; if meningeal metastasis occurs, meningeal irritation signs such as neck straightening may also appear. If rectal cancer spreads in late stage, when any discomfort occurs, one should consult doctor in time and cooperate with treatment, so as to reduce patients’ pain and improve the quality of survival.