Treatment after lung mediastinal lymph node surgery is based on the cause of hoarseness. Common causes include laryngeal recurrent nerve injury, vocal cord injury, cricoarytenoid joint dislocation, and so on. Commonly used treatments are conservative treatments such as general treatment, drug treatment and so on. 1. Laryngeal recurrent nerve injury: most of the laryngeal recurrent nerve can be restored to normal with vocal exercises and the use of nutritive drugs such as methylcobalamin and vitamin B1. If the hoarseness is caused by cutting off the recurrent laryngeal nerve due to improper operation during the surgery, it is very difficult to recover. 2. Vocal cord injury: Vocal cord injury caused by tracheal intubation, causing laryngeal congestion and edema, mostly transient, hoarseness can be gradually returned to normal. It is necessary to pay attention to a light diet and avoid loud talking. 3. Cricoarytenoid dislocation: tracheal intubation can also cause cricoarytenoid dislocation leading to hoarseness, which can be reset under laryngoscopy after the condition is stabilized, and generally can be restored to normal. There may be other reasons for hoarseness after mediastinal lymph node surgery, such as acute laryngitis, etc. It is recommended to improve the examination in time and standardize the treatment. The above drugs should be used under the guidance of a doctor, avoid self-medication.