Thymic hyperplasia mainly refers to thymoma, and a few are congenital thymic hyperplasia. Thymoma has the tendency of potential malignant transformation, therefore, once found, it should be surgically resected in a timely manner, and some patients may need radiotherapy and chemotherapy as the adjuvant comprehensive treatment. Congenital thymic hyperplasia is rare, but thymoma is very common. The latest guideline requires that thymoma be treated as a malignant tumor, and its treatment is based on open thoracic or thoracoscopic or mediastinoscopic surgical resection and comprehensive treatment with radiotherapy and chemotherapy. Once thymoma is detected, early surgery should be performed to completely remove the tumor and thymic tissues, including fat tissues in the mediastinum. Even if the tumor has invaded the surrounding tissues, surgical treatment can still be performed, and subsequent treatments, such as radiotherapy and chemotherapy, can be assisted after surgery. For patients who cannot undergo radical surgical resection or cannot tolerate surgery due to other reasons, radiotherapy and chemotherapy should be carried out, and at the same time, according to the specific symptoms, appropriate symptomatic supportive treatment should be carried out, e.g., pain relief, oxygenation, implantation of tracheal stent may be required for respiratory difficulties. Once thymoma is detected, surgical resection is recommended if the patient can tolerate surgery.