Chronic bronchitis is an inflammatory change of the trachea and bronchial mucosa caused by infection or non-infectious factors, with increased mucus secretion, and clinically characterized by long-term cough, expectoration or wheezing. The early symptoms of this disease are relatively mild, mostly in winter, relieved after the spring warmth, and the course of the disease is slow, so it is not noticed by people. When the late lesions progress and obstructive emphysema is complicated, lung function is damaged, which greatly affects health and labor. This disease is one of the common and frequently-occurring diseases in my country, and the age of onset is mostly over 40 years old. Smoking patients are significantly higher than non-smoking patients. The morbidity rate in my country is higher in the north than in the south, and the incidence rate in rural areas is slightly higher than that in cities.