Hemodialysis and peritoneal dialysis are currently the most widely used renal replacement therapies for the vast majority of patients with uremia. In patients with well-controlled extra-renal complications, uremic patients can survive for decades with adequate dialysis treatment. Dialysis therapy primarily uses the principles of diffusion and convection in physics. Hemodialysis includes three methods: conventional hemodialysis, hemofiltration and hemodialysis filtration. Conventional hemodialysis involves introducing the patient’s blood (containing high concentrations of uremic toxin) and dialysis fluid (without uremic toxin) into the dialyzer at the same time (the two flow in opposite directions), and the dialyzer is made of tens of thousands of hollow fibers bundled together. The wall of the hollow fibers is a kind of semi-permeable membrane with many small holes, and blood flows inside the hollow fibers The blood flows inside the hollow fibers and the dialysis fluid flows in the opposite direction outside the fibers. Then a proper negative pressure is applied on the dialysate side, and under the action of transmembrane pressure, water can also be removed from the body through the semi-permeable membrane, while small molecules such as calcium ions and bases in the dialysate enter the blood through the semi-permeable membrane. However, the medium and large molecules of toxins in the blood are not high in blood concentration, so the pressure difference between inside and outside the membrane is small, and the pore size of the semi-permeable membrane of the dialyzer is small, so conventional dialysis has a weak ability to remove medium and large molecules of toxins. Hemofiltration uses a filter membrane with larger pore size and applies strong negative pressure on the outside of the filter membrane during treatment. Under the effect of strong transmembrane pressure, a large amount of water in the blood mixed with various toxins of different molecular weights is removed from the body through the small pores on the filter membrane (tens of liters of plasma water can be removed in each treatment), while replenishing replacement fluid containing normal electrolytes and alkaline components. Hemofiltration is highly effective in removing medium and some large molecule toxins, but is less capable of removing small molecule toxins than hemodialysis. Hemodialysis filtration, on the other hand, combines the advantages of both methods, efficiently removing both small-molecule uremic toxins by diffusion and medium-molecule toxins and some large-molecule toxins by convection. Hemodialysis treatment is usually performed two to three times a week for four hours each time. Whether hemodialysis or hemofiltration treatment requires drawing the patient’s blood out of the body, the flow of blood in the extracorporeal circulation reaches 200 ml to 400 ml per minute, while the usual intravenous blood flow in the arm is only tens of ml, far from meeting the needs of treatment, so maintenance hemodialysis treatment requires patients to undergo autologous arteriovenous endovascular fistula surgery months in advance to meet the needs of long-term hemodialysis . However, for some patients with poor vascular conditions, arteriovenous endovascular fistulas are less effective. In addition, hemodialysis therapy is not recommended for patients with hypotensive shock, severe cardiac insufficiency or coronary artery disease, severe hypertension, severe bleeding tendency, or cerebral hemorrhage. Peritoneal dialysis therapy uses the peritoneum as a semi-permeable membrane and injects peritoneal dialysis fluid into the peritoneal cavity through a special peritoneal dialysis tube. This results in ultrafiltration and dehydration. Generally, peritoneal dialysis fluid is changed 3 to 4 times a day, and peritoneal dialysis fluid can be left in the abdomen overnight. Peritoneal dialysis is relatively smooth in the removal of water and toxins, does not depend on machines, is easy to perform, and is relatively inexpensive. Although the indications for peritoneal dialysis and hemodialysis are similar, each has its own advantages and disadvantages and should be selected according to the patient’s primary cause, condition, and medical and economic conditions. Peritoneal dialysis should be given priority in the following cases: ① those who are elderly and have poor cardiovascular system function; ② those who have difficulty in establishing vascular access for hemodialysis; ③ those who have serious bleeding tendency and cannot be hemodialysed for systemic heparinization; ④ those who have high urine output, peritoneal dialysis is more helpful in maintaining urine output and protecting residual renal function.