Dry rales are a long-lasting, “musical” respiratory sound. The dry rales have a long duration and can be heard in both inspiratory and expiratory phases, but they are more pronounced during expiration, and their intensity and nature can easily change, increasing or decreasing significantly within a few moments. Dry rales can be divided into high and low pitches according to their pitch. High-pitched dry rales, also known as whistling sounds, often have an ascending tone during forceful expiration and are mostly from smaller bronchi or fine bronchi, and are also called croup because they are more common in bronchial asthma. Low-pitched dry rales, also known as snoring sounds, mostly occur in the trachea or main bronchus. Dry rales that occur in the large airways above the main bronchus are not easily heard. The first thing is to quit smoking. Pay attention to keep warm, avoid getting cold and prevent cold. Improve environmental hygiene and personal labor protection to eliminate and avoid the effects of smoke, dust and irritating gases on the respiratory tract. Some patients can be controlled and do not affect work and study; some patients can develop obstructive lung disease and even pulmonary heart disease with poor prognosis. Changes in lung function in chronic bronchitis should be monitored in order to select an effective treatment plan and control the development of the disease in a timely manner.