The normal value of seventy-year-old blood oxygen saturation is 95% to 100%, 80% is much lower than the normal value, which may lead to hypoxia of vital organs, and at this time, it is not possible to not use the oxygen machine. Blood oxygen saturation is generally lower than 90%, representing the patient is in a state of hypoxia, seventy-year-old blood oxygen saturation of 80%, may lead to the heart, brain, kidneys and other important organs of hypoxia, which leads to metabolic disorders, the whole body’s acidosis, should be given mechanical ventilation in time to correct the blood oxygen saturation. If not treated with oxygen machine in time, as the patient’s blood oxygen saturation value continues to decline, it may lead to respiratory and circulatory failure, which may lead to the patient’s death. Seventy years of age with an oxygen saturation of 80% should be treated with prompt mechanical ventilation.