For ventilator-assisted respiratory therapy, there are non-invasive and invasive ventilators in use. For the use of non-invasive ventilators, the patient’s voluntary breathing is not affected. For patients with tracheal intubation with invasive ventilator-assisted breathing, the resumption of spontaneous breathing depends mainly on the patient’s primary disease and the severity of the disease. In the case of patients with chronic obstructive pulmonary disease, asthma, or severe pneumonia, the patient’s spontaneous breathing can be restored with active control of the primary disease and ventilator-assisted respiratory ventilation. Such patients should not use controlled ventilation mode for a long period of time to defeat the patient’s spontaneous breathing, otherwise it is difficult to recover spontaneous breathing and difficulty in deconditioning. For neuromuscular lesions, severe craniocerebral trauma, especially brainstem injury, spontaneous breathing is difficult to recover due to impairment of the respiratory center and respiratory drive, and only a few patients can recover partial spontaneous breathing by alternating the ventilator with controlled and assisted respiratory modes.