Hemofiltration refers to the removal of excess water and toxins from the body by not using dialysis fluid in the blood purification process, but by continuously replenishing a certain amount of replacement fluid in the vascular pathway to mix thoroughly with the blood and then performing ultrafiltration at the same rate. Compared to hemodialysis, hemofiltration has a lower hemodynamic impact and a higher clearance rate of medium-molecular substances. When hemofiltration is performed, vascular access is first established, usually through a venous vascular access, and blood is drawn from the vein, filtered out through a filter to remove blood toxins, and then the corresponding replacement fluid is returned to the body through the vein to ensure water-electrolyte and acid-base balance in the body.