As a systemic metabolic disease, diabetes mellitus has many complications. In China, 8% to 12% of blindness is caused by diabetic eye disease, and retinopathy is the most serious complication of diabetic eye disease that can cause blindness irreversibly. Due to the continuous damage to the lens, vitreous, fundus vascular nerve and other tissues by metabolic disorders such as hyperglycemia, more than half of diabetic patients with disease duration of more than 10 years will have combined ocular pathology. Among them, diabetic retinopathy, located in the fundus, has the highest incidence and is the most serious. Diabetic retinopathy is the result of long-term hyperglycemia, but patients with normal blood glucose are not necessarily “safe”. The incidence of diabetic retinopathy is higher the longer the duration of the disease, especially if it is accompanied by hypertension, hyperlipidemia, smoking, obesity or genetic factors, even if the blood sugar is relatively stable. Because diabetic retinopathy is a microangiopathy, early background retinopathy can be detected in 25% of type 2 diabetic patients at the time of initial diagnosis. Therefore, type 2 diabetic patients should be examined as soon as they are diagnosed; after the first specialist examination, patients should insist on a review at least once a year. For diabetic patients who have been found to have retinopathy, the fundus can be checked once every 4 to 6 months during the non-proliferative phase; once every 1 to 2 months during the pre-proliferative phase; and once every 2 weeks to 1 month during the proliferative phase. In addition, patients should detect symptoms as early as possible through routine fundus examination and fundus angiography in a timely manner. Clinical data show that early intervention and active and effective treatment before the development of fundus hemorrhage and retinal detachment, more than 90% of patients can lose their vision due to avoidance.