The main indications of bronchoscopic cryotherapy are as follows: 1, benign lesions: bronchial tuberculosis is more common, lesions can cause mucosal erosion, white spots attached, thus causing airway narrowing, through cryotherapy can achieve better results; 2, airway tumors: such as airway narrowing to a lesser extent, can be supplemented with cryotherapy, so that the tumor tissue necrosis, part of the necrotic tumor cells can promote the body to produce immunity, so as to fight against the deep tumor cells; 3, foreign body in airway: such as pills, sticky phlegm blockage, can also be cleaned up the airway through cryotherapy.