Extracorporeal circulation is a life-support technique that uses a series of special artificial devices to divert iatrogenic venous blood outside the body, which is artificially exchanged for gas, regulated for temperature and filtered for transfusion back into the arterial system of the body. The process of extracorporeal circulation is also called cardiopulmonary diversion because the artificial device replaces the body’s function, and the extracorporeal circulation machine is also called an artificial heart-lung machine. Extracorporeal circulation consists of a blood pump and an artificial lung. The function of the blood pump is to replace the function of the heart pump when the heart stops beating and is able to maintain blood circulation by diverting blood back from the veins and then pumping blood into the arteries. Artificial lung is to replace the function of the lungs, when the heart stops beating, blood does not flow through the lungs, play the function of gas exchange, expel carbon dioxide and inhale oxygen. 1.Blood pump: there are mainly roll-on pumps and centrifugal pumps. 2, artificial lung: mainly divided into two kinds of bulb type and membrane type. 3, a variety of cannula: including arterial cannula, intravenous cannula, left heart drainage tube, right heart suction tube, etc. 4.Filters: arterial microembolic filters and leukocyte filters, etc. 5, auxiliary devices: including oxygen saturation monitor, air oxygen mixer, liquid level alarm device, bubble alarm device, pressure alarm device, variable temperature blanket, etc. Modern artificial heart-lung machine has a very high technical standard and part of the artificial intelligence, with precise flow control function and digital operation monitoring function, the degree of blood destruction has been reduced to the lowest possible degree.