The clinical data of a patient with pulmonary mucoepidermoid carcinoma were collected， and the clinical characteristics， diagnosis and treatment methods of pulmonary mucoepidermoid carcinoma were discussed based on the review of relevant literatures.

The male patient aged 59 years old was admitted to the hospital because of “lung cancer discovered for more than 1 year and fatigue for 1 week”.The physical examination showed bilateral thoracic symmetry， no enhancement of speech tremor in both lungs， clear voice on percussion of both lungs， clear breath sounds on auscultation of both lungs， and no dry or wet rales. Based on the past history， a definitive diagnosis of pulmonary mucoepidermoid carcinoma was made. On admission， the chest CT results showed a mass shadow next to the mediastinum of the right upper lung with reduced density，the CT value was 29－43 Hu， blurred pleural margin， the size was 68 mm × 40 mm， the CT value after enhancement was about 73Hu in arterial phase， and the CT value was about 83 Hu in venous phase. Lymph node shadows were seen in the right hilum and mediastinum. Due to the previous operation， recurrence after chemotherapy， and unable to tolerate continued chemotherapy and targeted therapy， CT-guided argon-helium knife cryoablation was performed for the tumor in the right lung. The chest CT re-examination 1 month after the operation showed that the lesion was significantly reduced and the density was reduced. The value of CT was about 34 Hu， the size was 23 mm×26 mm， no obvious enhancement was seen after enhancement， and the right hilar and mediastinal lymph nodes were also smaller than before.

Pulmonary mucoepidermoid carcinoma is a special type of lung cancer with no obvious positive signs. High-grade pulmonary mucoepideromoid is prone to recurrence after surgery； the chemotherapy effect is poor， and there is no effective targeted drug therapy. Argon-helium knife cryotherapy can locally ablate the lesions， prolong the survival period，and improve the quality of life.