Cerebral infarction is a series of diseases that occur when the blood vessels in the brain, cerebellum or brainstem become obstructed in circulation for some reason, and ischemic necrosis occurs in the nerve cells of the brain due to prolonged vascular occlusion. Secondary prevention of cerebral infarction is to take preventive and treatment measures for patients who have already suffered from cerebral infarction, so as to improve the symptoms, reduce the death rate and disability rate, and prevent the recurrence of cerebral infarction at the same time. Secondary prevention methods of cerebral infarction include: 1. finding and controlling risk factors: for example, patients with hypertension should regulate blood pressure, try to make high pressure at 90-140 mmHg and low pressure at 60-90 mmHg; diabetic patients should have stable blood sugar control to avoid brain damage caused by too low or too high blood sugar; patients with hyperlipidemia should pay attention to low-fat diet; 2. improving living habits: patients need to quit smoking and alcohol, ensure Sleep, regularly review biochemical indexes, carotid ultrasound and other examinations to reduce the recurrence rate of cerebrovascular disease; 3. Systematic and regular medication: patients need to take antihypertensive, hypoglycemic, lipid-lowering, anti-platelet aggregation, lipid-regulating and plaque stabilizing drugs under the guidance of doctors, and do not arbitrarily adjust and stop medication to prevent the recurrence of cerebral infarction.