Diabetic patients with prolonged substandard blood glucose control can cause chronic complications of diabetes. Macrovascular complications are mainly manifested as coronary artery disease, angina pectoris, myocardial infarction, heart failure and arrhythmia. Cerebrovascular diseases manifest as lesions such as cerebral infarction, stroke, and cerebral stenosis. Lower limb vascular disease manifests as intermittent claudication, the appearance of diabetic foot combined with infection and gangrene, which can lead to amputation in severe cases. Diabetic microvascular complications, manifested as diabetic retinopathy, patients with blurred vision, vision loss, and in severe cases, can lead to detachment of the retina and lead to blindness. In patients with diabetic nephropathy, the early manifestations are urinary microalbumin, with gradual decline in kidney function and eventual uremia. Patients with diabetic peripheral neuropathy show symptoms such as numbness, pins-and-needles pain, burning sensation, and anthroposis in the lower limbs.