There is a clear correlation between cataract maturation and retinopathy severity in type 1 patients. The current view is that patients with clinically significant macular edema, severe non-proliferative diabetic retinopathy, or proliferative diabetic retinopathy should ideally undergo laser photocoagulation of the fundus prior to lens extraction. If the refractive interstitium is opaque and the fundus is not visible, then cataract extraction is necessary for retinal photocoagulation, and the surgery can allow laser treatment to be completed. Retinopathy is exacerbated after cataract surgery, and it is generally accepted that diabetic retinopathy progresses significantly over 3-6 months, with an increased risk of iris redness and neovascular glaucoma. In contrast, in non-cataract operated eyes, retinopathy progresses slowly or is relatively stable. Also taking into account the mode of cataract surgery, diabetic retinopathy due to extracapsular extraction progresses significantly less rapidly than intracapsular extraction. Diabetic patients must have their fundus checked before cataract surgery, and the following principles should generally be followed: 1. If cataract affects the treatment of fundus lesions, the cataract should be surgically removed as early as possible. 2. The degree of diabetic retinopathy should be estimated before cataract surgery to predict postoperative visual acuity. 3 If the refractive interstitial allows, patients with clinically significant macular edema, severe non-proliferative diabetic retinopathy or proliferative diabetic retinopathy should be considered for laser treatment before cataract surgery. 4. Eyes with proliferative diabetic retinopathy that cannot be treated with laser are not suitable for IOL implantation. 5. Patients with diabetic retinopathy should have their fundus checked immediately after cataract surgery. 6.Diabetic retinopathy will be aggravated after cataract surgery. 7.The earlier the fundus photocoagulation treatment after cataract surgery, the better, but the cataract surgery incision factor should be considered.