Hemoperfusion includes: 1. Direct hemoperfusion: the patient’s blood is drawn out of the body and returned to the patient’s body by adsorption through a perfusion device, simple hemoperfusion, usually for patients with poisoning; 2. Hemodialysis plus perfusion: a perfusion device is connected in series behind the dialysis machine, hemodialysis completes the removal of small molecules of toxins, and the perfusion device completes the removal of medium and large molecules of toxins, simulating the working principle of the kidney, called combined artificial kidney, suitable for patients with chronic renal insufficiency.