Patients with chronic renal failure have nitrogen retention in the blood. During the period of conservative treatment, it is necessary to cooperate with dietary therapy to limit protein intake to reduce nitrogen retention; reduce protein decomposition in the body, correct abnormal amino acid metabolism in the body, and maintain total nitrogen balance; ensure nutrition, enhance resistance, slow down the development of the disease and reduce complications. In order to achieve the above purposes, certain principles should be followed in the diet therapy. 1, consume low protein and high nutritional value of protein: that is, the amount of protein intake should be less but good quality, less but fine. The process of chronic renal failure can be blocked or delayed by limiting the amount of protein intake. Protein with high nutritional value is called high quality protein, which contains high amount of essential amino acids and produces less nitrogenous substances after decomposition in the body. Animal proteins, such as eggs, milk, lean meat, etc., should be used. Plant proteins generally contain more non-essential amino acids and have low biological potency, so they should be limited. In particular, staple foods such as corn and flour, which contain high levels of plant protein, should be more strictly controlled for those whose kidney function continues to deteriorate. The daily protein intake can be decided according to creatinine clearance (Ccr), such as Ccr10 ml/min, it should be 25-35 g per day. The staple food, in addition to rice and pasta, can also be combined with wheat starch (a product of flour after protein extraction, with a protein content of only 0.6%). At the same time, it should be noted that the whole day supply of high-quality protein food should be evenly distributed in 3 meals, in order to facilitate better absorption and utilization. 2, calorie intake should be sufficient: daily intake of about 8368 ~ 12552 kJ (2000 ~ 3000 kcal), the source of which mainly relies on sugar and fat. Changes in lipids in food can affect the progression of different types of kidney disease, where unsaturated fatty acids, such as linoleic acid, have been experimentally proven to prevent deterioration of kidney function. This is because linoleic acid is a precursor for the synthesis of prostaglandins and has a protective effect on kidney function by affecting prostaglandin levels. Therefore, in order to ensure the supply of unsaturated fatty acids in food, vegetable oils should be used instead of animal fats. 3, should pay attention to maintain the normal level of various vitamins: chronic renal failure patients due to loss of appetite, eating a diet containing vitamins too little; in addition, uremia itself can lead to changes in the metabolism of water-soluble vitamins, so patients with chronic renal failure should pay attention to the supplementation of vitamin B, vitamin C, etc.. And should not supplement vitamin A, because the body vitamin A elevated, can stimulate thyroid hormone secretion and cause renal osteodystrophy, can also cause fat metabolism disorders, resulting in cholesterol, triglyceride levels increase. In addition, chronic renal failure, 1, 25 dihydroxycholestrol production is insufficient, resulting in calcium, phosphorus and bone metabolic dysfunction, renal bone disease, so should also pay attention to the supplementation of vitamin D.