Congenital pulmonary cysts are intrapulmonary bronchial cysts that are classified into two types: solitary and multiple. It is the most frequent type of pulmonary malformation. There are more clinical subtypes, but most of the pulmonary cysts are connected to the bronchi and become air-containing fluid-containing cysts. Clinical manifestations: They may be asymptomatic when small in size and are often detected during physical examination on x-ray chest radiographs. When the volume increases, it will gradually produce occupying compression effect, and even mediastinal displacement and mediastinal hernia will appear. Once the lung cyst is connected with the bronchus, infection can easily occur, mainly manifested as fever, cough, shortness of breath, cyanosis and other symptoms of respiratory tract infection. Although it can be relieved by anti-inflammatory treatment, it is easy to recur and persist. Diagnosis: X-ray is an important means of diagnosis, and CT examination helps to clarify the location and size of the cyst and the adjacent lung tissues under pressure. Treatment: Cyst removal or lung lobectomy where the cyst is located should be performed as soon as possible after the diagnosis is confirmed.