Most of the patients with chronic renal failure still have some residual renal function. Protecting the residual renal function can reduce the frequency of dialysis, which is more conducive to the maintenance of water-electrolyte balance of the body and reduce the occurrence of cardiac insufficiency. (1) Actively treating the primary disease The degree of decline of residual renal function is slightly different in different causes of renal diseases. Early intensive insulin therapy in diabetic nephropathy can slow down the decline of residual renal function. In lupus nephritis, renal function may recover after hormone shock therapy, and even there are reports of longer time off dialysis. Purpura nephritis should actively search for allergens to prevent re-sensitization and aggravate renal damage. (2) Strictly control high blood pressure High blood pressure is a factor that promotes the progress of renal disease, especially dialysis patients, prone to water retention and lipid metabolism disorders, which are the risk factors of high blood pressure and renal arteriosclerosis, and controlling the blood pressure at a normal level can prevent further damage to the glomeruli. (3) Preventing hypotension in hemodialysis The amount of water removed in dialysis should not be too much, generally 5-7% of body weight is appropriate to prevent hypotension. Because insufficient effective blood volume can make the kidneys further ischemic and aggravate renal damage. Therefore, patients are required to control water intake between dialysis intervals. (4) Remove the obstruction factors of the kidneys Elderly men should pay attention to the treatment of prostate hypertrophy, kidney and ureteral stone patients should remove the stones as early as possible. (5) Avoid kidney damaging drugs and poisons Many drugs and poisons have kidney damaging effects. For example, aminoglycoside antibiotics, anti-tuberculosis drugs in the rifampicin, anti-tumor drugs adriamycin, fluorouracil, large doses of antipyretic and analgesic agents, such as: cold through, quick punch, contrast media, mannitol, traditional Chinese medicine GuanMuTong and GuangFuJi. Fish bile and heavy metal mercury in poisons. (6) Avoid high protein diet, high purine diet High protein diet has the effect of aggravating renal burden. A low protein diet should be appropriate in the non-dialysis period of renal failure. But dialysis patients due to small molecules of nutrients will be lost through the filtration membrane, so it is not recommended low protein diet, should be given under the guidance of the physician appropriate higher protein diet to prevent malnutrition. High purine diet can make uric acid production increase, the formation of uric acid crystals blocking renal tubules damage to the kidneys. These foods include: animal offal, seafood, fish eggs, fish skin, beer, soybeans, seaweed, shiitake mushrooms, spinach and so on.