Abstract: Thyroid-associated ophthalmopathy is an autoimmune disease with unclear mechanism. Radiotherapy has certain curative effect to relieve the eye symptoms. Usage of traditional radiotherapy technology might be the reason of no discernible improved efficiency. However, with the progress of radiotherapy, it is found that more problems like target volume, dose and radiotherapy which is especially stressed deserves further investigation. Compared with the traditional radiotherapy, the modern radiotherapy is featured with even dose distribution in target volume and large dose gradient outside target volume. Therefore, it is more helpful in improving efficiency and protecting normal tissue.