Case Sharing: Mr. Ye is 52 years old and has been coughing and sputum repeatedly for more than 20 years. Half a month ago, the symptoms suddenly worsened and hemoptysis began to appear. He had been misdiagnosed as chronic bronchitis and bronchodilatation for a long time in an outside hospital. He was transferred to our hospital for further treatment. After admission, chest CT showed high density shadow in the left lower bronchus and large flocculent shadow in the lower lobe of the left lung with irregular cavity. Under general anesthesia, bronchoscopy was performed, and a black irregular foreign body was seen in the opening of the basal segment of the left lower lobe, and granulation tissue was seen around it. The granulation tissue was separated with biopsy forceps, and after the foreign body was loosened, the sharp end of the foreign body was clamped with foreign body forceps, and the foreign body was slowly pulled and taken out through the trachea and the vocal folds. The foreign body was an animal bone (pork ribs), about 2.5cm×1.0cm. Tracheal foreign body is a foreign body that is mistakenly inhaled into the trachea or bronchus and cannot be coughed up by itself. There are many different types of foreign bodies, including animal bones, fish spines, metal objects, dentures, etc. They are commonly found in children and account for a large proportion of childhood injuries. It is common in children and accounts for the third largest number of unintentional injuries in children. Perennials are relatively rare. In the elderly, the incidence increases due to sluggish pharyngeal reflexes and poor airway sensitivity. The clinical manifestation of airway foreign body varies greatly, patients may have no clinical symptoms, or manifested as coughing, coughing up sputum, hemoptysis and other manifestations, and in severe cases, chest pain, shortness of breath, or even suffocation and death. If the patient has a history of inhalation of suspicious substances such as choking, coughing, coughing up sputum, dyspnea and other manifestations, should be alert to the airway foreign body; recurring localized obstructive pulmonary inflammation, pulmonary atelectasis, etc. should be timely tracheoscopy to exclude the possibility of airway foreign body. Lesson: This case has a long history of foreign body obstruction of the left lower lobe bronchus, which led to repeated distal infections and ultimately caused the formation of lung cavities, and was easily misdiagnosed as bronchiectasis and pulmonary distension. This patient is a typical case of long-term misdiagnosis, and failure to perform timely bronchoscopy is the main reason for misdiagnosis. High density shadow in the left lower bronchus, large flocculent shadow in the left lower lobe of the lung, and irregular cavity in the left lower lobe A black irregular foreign body in the basal segment of the left lower lobe The foreign body was an animal bone, about 2.5cm×1.0cm.