The normal value of the inferior vena cava collapse rate is usually 1, indicating that the inferior vena cava is in normal condition. The inferior vena cava collapse rate is a method of evaluating the patient’s volume loading using bedside ultrasound, if the patient needs to know more about the above situation, it is recommended to go to the outpatient clinic of the Department of Cardiology or Cardiac Surgery of the hospital, and dispose of it under the correct guidance of the doctor. Inferior vena cava collapse rate is mainly to observe the image of the inferior vena cava into the right atrial opening, and to observe the changes of the inferior vena cava distal to the opening of the right atrium with the respiratory movement, which refers to the ratio of the narrowest to the widest of the inferior vena cava, and the normal value is usually 1. If the inferior vena cava collapses more significantly, the ratio of the inferior vena cava collapse rate may exceed fifty percent, which usually indicates that the patient is hypovolemic and rehydration therapy is recommended. If the collapsed inferior vena cava ratio is zero, it may indicate that the patient’s blood volume is too large, and the patient needs to be treated with diuretic drugs such as furosemide, spironolactone, etc., and vasodilator drugs such as sodium nitroprusside, captopril, etc., to reduce the cardiac load.