The main clinical causes of left vocal cord fixation are as follows: the first cause, malignant tumors in the larynx invade the vocal cords, causing them to appear fixed. The common clinical causes are laryngeal cancer and hypopharyngeal cancer, which invade the vocal cord muscle and lead to vocal cord fixation. The second reason is that some patients have thyroid surgery that damages the recurrent laryngeal nerve, or huge tumors of the thyroid gland that compress the recurrent laryngeal nerve, resulting in vocal fold fixation. The third reason is that some patients have esophageal cancer, lung cancer, or mediastinal lymph node metastasis, which compress the laryngeal nerve and cause vocal cord fixation. For the fourth reason, some patients have cerebral hemorrhage, cerebral infarction sequelae or intracranial occupying tumor compression lesions, resulting in left vocal fold fixation. The fifth reason is that some patients have unexplained causes of left vocal fold fixation, which may be caused by viral infections, etc. In conclusion, the left vocal fold fixation should be clinically perfected by CT of the head and neck, CT of the chest esophagus and lungs, as well as electronic laryngoscopy and ultrasound of the neck and other related examinations to determine which cause of vocal fold fixation the patient belongs to.