Patients with stage 4 diabetic nephropathy have seen a decline in kidney function, and reasonable dietary treatment can delay the continued progress of kidney function. In dietary treatment, the first thing is to limit the total daily caloric intake, which should meet the normal physiological needs of the body, depending on the patient’s activity status, and strictly limit the intake of carbohydrates and sugar, with the aim of controlling blood sugar. It is also necessary to strictly limit the protein intake and increase the proportion of high quality protein under the premise of strictly limiting protein intake, and to eat regularly every day, eat less and more meals, and exercise more. Also pay attention to low salt and low fat diet, the amount of salt intake and supply in the diet should be adjusted with the changes of the disease. If the increase of blood pressure is obvious and edema is obvious, the salt intake must be limited. For water, the amount of water intake should be strictly controlled and the amount of water should be measured. Attention should also be paid to the adequate intake of vitamins and appropriate calcium supplementation.