Chronic cough is one of the most common complaints in respiratory specialty clinics, imposing significant economic burden on patients and severely affecting their quality of life. Currently, the pathogenesis of chronic refractory cough remains incompletely understood, and treatment remains a major challenge in clinical practice. Cryotherapy treatment via bronchoscopy has shown efficacy in certain airway diseases, but there is currently no research reporting its effects on chronic refractory cough. The goal of this clinical trial is to learn if Cryotherapy treatment works to treat individuals with chronic cough. It will also learn about The safety and effectiveness of the cryotherapy treatment system produced by Ningbo SensCure Biotechnology Co., Ltd.. The main questions it aims to answer are: * Does cryotherapy treatment lower the frequency and severity of cough and enhance quality of life? * Will there be safety or operational performance issues when using this cryotherapy treatment system? Researchers will compare cryotherapy treatment with no treatment to determine if cryotherapy treatment is effective for treating chronic cough. Participants will: * Take routine bronchoscopy examination, lavage, and mucosal biopsy ,with/without cryotherapy treatment locally (around the left and right main bronchi, upper trachea, and carina) * undergo a screening period of approximately 28 days. Follow-up visits and necessary examinations will be scheduled for the 3rd day after treatment initiation and at weeks 1, 2, 4, 8, and 12 thereafter. * Monitor vital signs and clinical manifestations.