Pulmonary cyst is a cystic lesion, specifically a cystic lesion containing gas of varying sizes, or fluid gas in the lung, and is a benign lesion that includes congenital and secondary pulmonary cysts. Congenital pulmonary cysts are mainly caused by congenital embryonic dysplasia, while acquired pulmonary cysts are mainly secondary to some lung infections. Most pulmonary cysts do not cause clinical symptoms and do not require treatment if they are not complicated by infection. In case of huge pulmonary cyst, it can compress the lung tissue and make the lung function decrease, causing symptoms of chest tightness and dyspnea, or in case of complicated infection, it can cause symptoms such as cough, fever and hemoptysis, which need surgical treatment and anti-infection treatment.