Plasma replacement is mainly a blood purification therapy to remove macromolecules, which is to draw the patient’s blood out of the body by a blood pump, pass through a plasma separator, separate the plasma and cellular components, quickly remove the disease-causing plasma and certain disease-causing factors in the plasma, and then transfuse the plasma and the required replacement fluid back into the patient after the cellular components are purified. It is commonly used clinically in diseases such as pulmonary hemorrhagic nephritis syndrome, myasthenia gravis, Green-Barre syndrome, cryoglobulinemia, macroglobulinemia, familial hypercholesterolemia, drug overdose, poisoning with protein-bound toxicants, neonatal hemolytic disease, autoimmune hematologic disease, and chronic severe hepatitis.