Diabetes mellitus plus cerebral infarction is more dangerous, because cerebral infarction itself is a serious ischemic stroke, which can cause severe neurological deficits, including impaired consciousness, speech impairment, cognitive impairment, bulbar palsy, central facial and tongue palsy, hemiparesis, hemianesthesia and hemianopia, etc. If the patient is combined with diabetes mellitus, it will not only aggravate the damage of large blood vessels, but also cause blood flow disorders in the microcirculation of the brain If the patient has diabetes mellitus, it will not only aggravate the damage of large blood vessels, but also cause blood flow disorders in the microcirculation of the brain, which will affect the blood flow reconstruction of the brain and the recovery of brain nerve function. Hyperglycemia also causes an increased incidence of complications of cerebral infarction, including pulmonary infection, urinary tract infection, skin infection, cerebral edema, epilepsy, lower limb venous thrombosis, etc., which makes the treatment and recovery of the disease very difficult. Therefore, patients with cerebral infarction combined with diabetes mellitus should strictly control blood sugar while actively treating cerebral infarction.