Diabetes is a common disease that can cause lesions in various tissues of the eye, and retinopathy is the most serious complication of diabetic eye disease that is irreversible. Diabetic retinopathy is associated with the duration of the disease and the degree of glycemic control, while age, gender and type of diabetes are less relevant. Diabetic retinopathy is the leading cause of blindness in patients over the age of 50 in Western countries. In China, with the improvement of people’s living standards and the significant increase of human life expectancy, the total number of diabetics in China increases by at least one million people every year. According to a group of epidemiological survey data from the former Shanghai Medical University, the incidence of diabetic retinopathy is 28% for those with a disease duration of less than 5 years, 36.4% for those with a disease duration of 6-10 years, 58% for those with a disease duration of 11-15 years, and 72.8% for those with a disease duration of more than 15 years. Diabetic retinopathy has no conscious symptoms in the early stage, and there are varying degrees of vision loss after the lesion involves the macula. The intraretinal barrier is destroyed, capillary occlusion, producing microangiomas, retinal hemorrhages, exudates, absorbent cotton spots, macular cystoid edema; due to large capillary occlusion, retinal microcirculation is impaired, blood flow is severely deficient, tissue is severely hypoxic and metabolism is impaired, and the retina produces vascular growth factor, leading to the production of neovascularization tubes, which are only tubes surrounded by simple endothelial cells, with no surrounding connective tissue. There is no supporting connective tissue around them, no basement membrane, and no receptors to sense blood flow or blood pressure. Due to incomplete wall development, these vessels are brittle and prone to rupture and hemorrhage under the action of numerous local factors. In proliferative diabetic retinopathy, neovascularization can grow between the inner border membrane and the posterior vitreous border membrane, forming a fibrovascular membrane. Due to the special structure of neovascularization, its wall is unstable and prone to hemorrhage, so a large amount of hemorrhage can enter the vitreous and produce mechanized material, leading to retinal detachment and blindness. Laser photocoagulation therapy can alleviate or remove the onset and development of retinal ischemic edema and neovascularization to some extent, and is still an effective treatment for macular degeneration and neovascularization in diabetic retinopathy. The results of the American Early Treatment Diabetic Retinopathy Study showed that clinically significant macular edema reduced the risk of moderate vision loss by more than 50% after macular laser treatment, and a small percentage of patients had improved vision, but in most patients, the purpose of laser treatment was to stabilize the existing visual acuity. Generally speaking, diabetic retinopathy disease stage I and II do not require laser treatment, stage III and IV are the best applicable period for treatment, stage V and VI photocoagulation treatment complications and poor results, or consider glass vitrectomy plus photocoagulation treatment.