Brain metastasis of colon cancer may have symptoms such as dizziness, headache, vomiting, blurred vision and impaired consciousness. Colon cancer is a common malignant tumor in gastrointestinal tract and patients have no obvious symptoms in early stage. Brain metastasis may occur in late stage colon cancer, and different clinical manifestations may appear according to different foci of brain metastasis. When the brain metastatic lesion is relatively large causing occupying effect, causing increased intracranial pressure, dizziness, headache, projectile vomiting, optic papilla edema, blurred vision and other symptoms may appear. When colon cancer metastasizes to the functional area part of brain, it can cause corresponding symptoms, including hemiplegia, aphasia, drowsiness, coma and so on. When colon cancer patients develop brain metastasis, their condition is more serious and the prognosis is usually worse. If the brain metastasis is relatively small and single, surgery can be considered and supplemented with chemotherapy, radiotherapy and other comprehensive treatments after surgery. However, if the lesions are more numerous and cannot be surgically resected, radiotherapy, chemotherapy and other treatments need to be given in time to alleviate the patient’s symptoms and prolong the survival period. Patients with colon cancer should pay attention to symptoms such as dizziness and projectile vomiting and consult doctor in time. Early detection, early diagnosis and early treatment can effectively improve the prognosis of the disease.