Oxygen concentrator and ventilator are not the same, oxygen concentrator is mainly to improve the concentration of oxygen to improve the patient’s hypoxemia, ventilator is used to assist respiratory ventilation. Whether to use a ventilator or an oxygen concentrator for patients with chronic obstructive pulmonary disease depends on the severity of the disease, if the condition is mild, then the use of an oxygen concentrator can be used for home oxygen therapy; if the condition is critical, then the use of a ventilator is required. If patients with COPD have hypoxemia, the body is in a chronic hypoxic state, requiring long-term low-flow (1-2L/min) oxygen intake, which should be guaranteed for at least 15 hours a day. If the patient’s hypoxemia is mild and not accompanied by hypercapnia, home oxygen therapy with an oxygen concentrator can be given. If the patient shows severe hypoxemia and hypercapnia, ventilator-assisted ventilation is required. If patients with chronic obstructive pulmonary disease have hypoxemia with or without hypercapnia, they need to go to the hospital in time and choose the appropriate treatment plan under the guidance of the doctor, and do not treat blindly, so as not to delay the condition.