Diabetic retinopathy is one of the three major blindness-causing eye diseases in China. According to the statistics, the incidence of diabetic retinopathy is 35-39% for those with a disease duration of less than 5 years, 50-56.7% for those with a disease duration of 5-10 years, and 69-90% for those with a disease duration of more than 10 years. The incidence is higher if there is a combination of hypertension, hyperlipidemia and significant changes in hemodynamics. The incidence of oral hypoglycemic drugs is 60% for those with 20 years of type II diabetes and 84% for those with insulin injections. It is evident that the existing glucose-lowering drugs do not reduce its occurrence and progression. Although it is controversial whether diabetic retinopathy can improve or regress with the control of diabetes, there is little doubt that patients with higher glucose levels, i.e. severe or poorly controlled diabetes, have more severe retinopathy. Many scholars believe that if the glycemia and systemic condition of diabetic patients are well controlled, it is certainly beneficial in delaying the onset, progression and reduction of diabetic retinopathy. The current international treatment of diabetic retinopathy is classified according to its severity: mild, moderate, severe non-proliferative diabetic retinopathy and proliferative diabetic retinopathy. Clinical diagnosis is based on fundus photography and fundus fluorescence angiography. For mild to moderate nonproliferative early long-term administration of aspirin 300 mg/day and calcium hydroxybenzoate 500-1000 mg/day may be beneficial in the prevention and treatment of diabetic retinopathy, but close follow-up is necessary because the risk of developing proliferative is very high. Fundus laser is considered to be the most effective method for the treatment of diabetic retinopathy. Clinical trials have demonstrated the beneficial effects of photocoagulation on the pathogenesis of the disease in 2 ways: first, by causing degeneration of neovascularization and preventing their regeneration; and second, by reducing macular edema. The former is for proliferative lesions and the latter is for non-proliferative lesions. For severe non-proliferative and proliferative diabetic retinopathy with neovascularization in the retina or optic disc, total retinal photocoagulation should be performed immediately to prevent neovascular hemorrhage, reduce the risk of deterioration, reduce the threat of blindness, and prevent complications, and regular follow-up and review should be performed after photocoagulation. Proliferative diabetic retinopathy with combined vitreous hemorrhage and retinal detachment requires vitreous surgery and intraocular photocoagulation to save vision. It is generally accepted that vitrectomy is required in cases of extensive vitreous hemorrhage that cannot be spontaneously absorbed for more than 3 months. However, clinical practice has proven that postponement of surgery is detrimental, and early implementation of vitrectomy for a recent severe vitreous hemorrhage is much more likely to restore good vision than postponement of surgery. The reason may be to prevent distortion or detachment of the retina, especially the macula, due to hemorrhage mechanization, adhesions, and traction. If neovascularization and fibrous proliferation have been found to be more extensive before the vitreous hemorrhage, vitrectomy should be performed even earlier. The best time to perform the procedure is half to one month after the hemorrhage. For retinal detachment without vitreous hemorrhage but with severe proliferative lesions or involving the macula, vitrectomy is also feasible. The aim is to release the involvement, destroy the neovascularization by intraocular electrocoagulation or photocoagulation, and reset the detached retina by intraocular injection of filling. Diabetic patients are generally aware of the importance of blood glucose control, but often neglect eye changes and rarely go for eye examinations. It is generally believed that once diabetic retinopathy occurs, it is a lifelong complication that accompanies diabetes. When patients find changes in vision and then go to the ophthalmology examination, often there are already lesions in the fundus of the eye, often missing the best time for treatment. Therefore, ophthalmologists urge: internal medicine doctors and ophthalmologists to work closely together, and patients who have been diagnosed with diabetes should receive timely and regular eye examinations, and if lesions are found, they should be treated promptly. It is recommended that diabetic patients without diabetic retinopathy should have their fundus examined once every 6 months to once a year; non-proliferative diabetic retinopathy should have their fundus examined every 1 to 3 months and be treated prophylactically; patients with proliferative diabetic retinopathy should visit the ophthalmology department once every half month to once a month.