Pulmonary cavitary lesions are pathologic cavities in the lungs caused by alveoli, cysts, air sacs, and other factors. Pulmonary cavitary lesions are mainly the appearance of many cavities in the lungs, especially as a result of pathologic factors, i.e., the pathological enlargement of physiologic cavities. The most common causes of this lesion are large pulmonary alveoli, pulmonary cysts and air sacs, the presence of edema in the mucosa of the small bronchi, ruptured emphysema, and benign lung cysts. Inflammatory lesions result in partial obstruction of the lumen of the tubes, which creates a flap effect, allowing air to enter the alveoli without being easily expelled, so that the pressure inside the alveoli is increased. X-ray film of the lungs and pulmonary function tests can be used to clarify the cause and determine the condition, and timely symptomatic and etiologic treatment can be provided after diagnosis.