In recent years, with the improvement of living standards and lifestyle changes, the incidence of diabetes has become epidemic, and the number of people with diabetes has reached 194 million worldwide, and is expected to reach 330 million by 2025. The incidence of diabetes in China is also increasing year by year, and a national epidemiological survey organized by the Chinese Medical Association in 2010 showed that the number of people with diabetes has reached 94 million. Because type 2 diabetes is insidious, some patients often have kidney disease or eye disease as the first symptom, and only after going to the hospital for examination is the presence of diabetes discovered. As the number of people with diabetes increases, the number of complications caused by diabetes also increases year by 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 was 58.6% in 2005. Diabetic nephropathy is a multifaceted clinical syndrome characterized primarily by persistent albuminuria and progressive renal hypofunction as the disease progresses. Diabetic nephropathy is a progressive process with different manifestations at different stages. It is usually divided into 5 stages: Stage 1, which is characterized by glomerular hyperfiltration and some patients may have a soreness and swelling in the lower back, often when type 1 diabetes is diagnosed; Stage 2, in which urinary microalbumin appears intermittently and glomerular filtration returns to the normal range; Stage 3, also known as early diabetic nephropathy, is characterized by persistent and increasing urinary microalbumin, which cannot be detected by ordinary urine routine and must be detected by special methods. Once clinical proteinuria appears, the majority of patients’ renal function gradually decreases and will progress to end-stage renal disease, renal insufficiency – diabetic nephropathy stage 5 within the next 5 years. During the progression of renal failure, urinary protein excretion does not decrease and coexists with nephrotic syndrome. Patients are often combined with anemia and malnutrition, which makes medical treatment very difficult and often requires kidney transplantation or dialysis treatment to maintain life. However, early detection can reverse or slow down the progression of diabetic nephropathy. Therefore, the detection of early diabetic nephropathy patients is the key to the prevention and treatment of diabetic nephropathy. Screening indicators for diabetic nephropathy include microalbuminuria, renal function and fundus examination. The early diagnosis of diabetic nephropathy is mainly based on microalbuminuria. Three 24-hour urine microalbumin test results ≥ 30mg/24h within six months are considered to have diabetes combined with kidney damage, and if fundus lesions are also present, diabetic nephropathy is considered to be more likely. Next is the blood creatinine level in the renal function, according to which the value of glomerular filtration rate can be calculated. Glomerular filtration rate is the main indicator to determine the status of renal function. For patients whose diagnosis of diabetic nephropathy is in doubt, renal puncture biopsy can be performed when necessary to clarify the diagnosis. The treatment of diabetic nephropathy is more about prevention than cure. Blood sugar, blood pressure, blood lipids and disease duration are the main influencing factors. Therefore, first of all, we should strengthen the control of blood sugar, requiring glycated hemoglobin to be controlled below 6.5%; blood pressure to be controlled below 130/80mmHg; and blood lipid to be controlled in normal range; only in this way can the possibility of diabetic nephropathy be reduced to the minimum. Secondly, close monitoring is required. In general, patients with type 1 diabetes who have had the disease for more than 5 years should have their urine microalbumin tested at least once a year; for patients with type 2 diabetes, due to its insidious onset, urine microalbumin testing should be routinely performed once a year at the beginning of the discovery of diabetes.