Posterior replacement is generally better than anterior replacement when hemofiltration is performed. Hemofiltration is the process of blood purification by using a machine (pump) or the patient’s own blood pressure to cause the blood to flow through a filter in the extracorporeal circuit, which filters out a large amount of liquid and solute, i.e., ultrafiltrate, under the action of filtration pressure; at the same time, it replenishes electrolyte solution with similar composition to plasma liquid, i.e., replacement solution. Anterior replacement is replacement fluid input before the filter, and posterior replacement is replacement fluid input after the filter. Anterior replacement has low resistance to blood flow and is not easy to clot, while posterior replacement, on the contrary, is easy to clot and has high resistance, and more heparin is used to prevent clotting. The advantage of posterior replacement is that it has a high clearance rate, reduces the amount of replacement fluid, and saves treatment costs. Patients in the treatment period should go to regular hospitals regularly, regular review, should always observe their own physical condition, follow the doctor’s instructions to adjust the treatment program.