Myasthenia gravis is a disease characterized by dysfunction of transmission at the neuromuscular junction. It is characterized by fatigue of the affected skeletal muscles and weakness, with symptoms that are mild in the morning and severe at night and can be alleviated after rest. About 80% of patients have thymic hypertrophy, of which 10% have thymoma. Surgical excision of thymus and anterior mediastinal adipose tissue is a reliable method to cure myasthenia gravis, with high cure rate and good long-term results. In the course of myasthenia gravis, early thymectomy is the most valuable, and those with thymoma should be removed surgically, as studies have shown that 86% of patients with myasthenia gravis will eventually develop a generalized type, and surgery is most effective within one year of onset. However, the traditional surgical method requires sawing through the sternum, which is traumatic, painful and leaves a 20 cm-long surgical scar on the anterior chest, which is daunting to many patients. In 2008, our department started to carry out expanded thoracoscopic thymectomy to treat severe myasthenia gravis, and has accumulated rich experience so far, curing patients as young as 6 years old and as old as 57 years old. Compared with the classic median sternal approach, thoracoscopic thymectomy has small and hidden incision, no obvious surgical scar, good cosmetic effect, less bleeding, less trauma, quick recovery, no metal foreign body left in the body after surgery, better effect than traditional open-heart surgery, and significantly less trauma, more hidden and beautiful incision, which is a blessing for the majority of patients with myasthenia gravis. The indications for expanded thoracoscopic thymectomy include: patients with myasthenia gravis who have poor medical results, especially for adolescents, children, young women and elderly patients who cannot tolerate open-heart surgery; female patients with the disease starting from 20 to 30 years old have more obvious improvement in symptoms after thymectomy, and about 70% of patients with myasthenia gravis have their symptoms relieved or cured after thymectomy. Myasthenia gravis combined with thymoma Complete resection of bilateral thymus and mediastinal fat Surgical incision and drainage tube Comparison with conventional surgical incision