The patient, an 11-year-old girl, was admitted with recurrent fever for 20 days, worsening with abdominal distension for 7 days. Upon admission, she presented with recurrent fever, lymphadenopathy, hepatosplenomegaly, polyserositis, and multiple organ dysfunction. Lymph node pathology and clinical manifestations confirmed the diagnosis of idiopathic multicentric Castleman disease-TAFRO syndrome. Treatment with siltuximab combined with glucocorticoids was initiated, followed by maintenance therapy with tocilizumab. The patient is currently in complete clinical remission. Therefore, once a child is diagnosed with idiopathic multicentric Castleman disease -TAFRO syndrome, early use of siltuximab should be considered for rapid disease control, followed by tocilizumab for maintenance therapy.