This study is a randomized, controlled, multi-center clinical study, the purpose is to evaluate the efficacy and safety of rapamycin combined with methylprednisolone in the treatment of moderate to severe active GO. GO patients with moderate to severe activity were selected as the research objects, and the screening period was 1 week. Eligible and well-informed subjects were randomly assigned 1:1 to the experimental group (rapamycin + methylprednisolone) or the control group (methylprednisolone group). The control group was given methylprednisolone pulse 500 mg/time once a week for 6 weeks + 250 mg/time once a week for 6 weeks, and the experimental group was given rapamycin 2 mg/day orally for 24 weeks on the basis of methylprednisolone pulse therapy. The follow-up period was from 25th to 36th week. Before treatment, 1 week after treatment, 6 weeks, 12 weeks, 24 weeks, and 36 weeks, visits were conducted to evaluate the improvement and safety evaluation of patients' GO eye activity, severity, and quality of life. At the end of the 1st week and the 12th week, the blood concentration of rapamycin was measured.