• Study participants will be selected for this study only if they meet all of the following criteria:

‣ Age ≥18 years old and ≤80 years old;

⁃ The subject signs the informed consent form, is willing and able to comply with the protocol, complete the research assessment and return for follow-up;

⁃ To be diagnosed as a patient with systemic MG, the patient is required to have positive myasthenia-related antibodies (AChR-Ab, Musk-Ab or LRP4) on the basis of typical myasthenic symptoms;

⁃ Evaluated by the researcher as refractory MG. Refractory MG is defined as:

• Treatment failed after receiving at least 2 immunosuppressants

∙ Definition of treatment failure: 1) Persistent weakness and impairment of daily activities; 2) MG aggravation and/or crisis during treatment; 3) Intolerance to immunotherapy due to side effects or comorbidities;

∙ Repeated plasma exchange (PE) or intravenous immune globulin (IVIg) treatment is required to control symptoms;

∙ The researchers believe that despite the current routine immunotherapy for patients, MG still imposes a large functional burden on patients.

⁃ MGFA classification IIa\

⁃ IVa at screening and baseline;

⁃ QMGS score ≥11 points or MG-ADL score ≥5 points at screening and baseline, of which the eye score accounts for no more than 50%;

⁃ Male study participants must agree to take contraceptive measures during the treatment period and within 1 year after receiving study treatment, and are prohibited from donating sperm throughout the study period;

⁃ If you are a woman of childbearing potential (WOCBP), you must agree to take contraceptive measures during treatment and for at least 1 year after receiving study treatment. Participants must have a negative serum pregnancy test result during screening; a negative urine pregnancy test result must be confirmed before receiving CART for the first time.