As the population base of diabetes increases, the number of complications caused by diabetes is also increasing every year. Chronic complications of diabetes have become a threat to human health. Among them, diabetic nephropathy is an important microvascular complication. Domestic and international epidemiological studies show that 30% of diabetic patients have diabetic nephropathy, and the prevalence of proteinuria in patients with type 2 diabetes combined with hypertension in Asia is as high as 58.6%, according to a 2005 study. Studies in the United States have shown that 54% of end-stage renal disease patients newly started on dialysis have diabetic nephropathy, 90% of which is caused by type 2 diabetes. Once diabetes and kidney damage enter end-stage renal disease, not only is the cost of renal replacement therapy high, but the mortality rate is also high, with a 5-year survival rate of only 50% for dialysis patients. Early detection and timely intervention can effectively slow down the development of diabetic nephropathy. However, early diabetic nephropathy has no specific clinical manifestations, so it must be detected by early screening. Screening should be started at the same time as the diagnosis of type 2 diabetes and for those who have had type 1 diabetes for more than 5 years. Screening for diabetic nephropathy is particularly important in people with high blood sugar, high blood pressure, smokers, high dietary protein intake, and a tendency to cluster in families. People with the following symptoms should be screened for diabetic nephropathy: weakness, low back pain, swollen lower eyelids, foamy urine, and decreased vision. Diabetic nephropathy is a clinical syndrome with multiple manifestations, the primary clinical feature being persistent albuminuria and progressive renal hypofunction as the disease progresses. Therefore, the screening of diabetic nephropathy is cut into these two points. First of all microalbuminuria, which is the leakage of albumin from the blood from the kidneys, is detectable in the urine. Because the amount is small in the early stage, it is not easily detected in normal urine routine and requires a special hair method to detect it. There are usually two types of urine tests: random urine and 24-hour urine test. A random urine test requires simultaneous measurement of urine creatinine and calculation of the ratio (urine microalbumin/urine creatinine, ACR); ACR > 30mg/g or 24h urine microalbumin > 30mg/24h is considered abnormal. More than 2 tests are often required because of the number of factors affecting protein excretion in urine. Next, blood creatinine. Blood creatinine represents the status of kidney function. According to the guidelines published by the American Kidney Foundation, the value of glomerular filtration rate can be calculated from the blood creatinine value by using the MDRD formula. An estimated glomerular filtration rate of <90 ml is considered to have mild renal decline, 60-90 ml is moderate renal decline, and <60 ml is considered to be renal insufficiency. Fundus photography. Diabetic retinopathy and nephropathy are both microvascular complications of diabetes mellitus. Examination of fundus lesions can help identify the cause of renal damage. Routine urine testing. Since urinary tract infections can affect the detection of urine microalbumin, simultaneous urine tests can help to rule out false positives caused by infectious factors. In conclusion, paying attention to screening for diabetic nephropathy can help detect patients with early diabetic nephropathy, seize the opportunity for treatment, reduce the proportion of patients delaying entry into dialysis, and improve the prognosis of patients with diabetic nephropathy.