Hypercapnia is due to lung ventilation dysfunction, and common causes include chronic obstructive pulmonary disease and severe bronchial asthma. The use of a ventilator can have an ameliorating effect on hypercapnia. Respiratory acidosis occurs when the partial pressure of carbon dioxide in the body is too high. When acidosis occurs, the binding capacity of hemoglobin and oxygen in the body decreases, further aggravating hypoxia, which can lead to further deterioration of carbon dioxide retention, forming a vicious circle. Ventilator is a device that can replace, control and change the patient’s original respiratory rhythm, increase ventilation, improve respiratory function, effectively deliver oxygen to the body, and expel the carbon dioxide retained in the body. Therefore, it is possible to improve both hypoxia and hypercapnia at the same time. The use of a ventilator for high carbon dioxide is helpful, but there are contraindications to the use of a ventilator, and patients are advised to choose the appropriate treatment under the guidance of a doctor.