Systemic lupus erythematosus （SLE） complicated refractory immune thrombocytopenia （ITP） is mainly characterized by persistent severe thrombocytopenia and bleeding. Currently， there are no guidelines for treating such ITP. Hereby we reported a patient diagnosed with SLE with more than 10 years history of anemia and thrombocytopenia. This patient had been treated by various immunity inhibitors， such as corticosteroids， cyclosporine， mycophenolate mofetil， azathioprine， tofacitinib and telitacicept， but there was no obvious effect. The platelet count continued to be below 50×10⁹/L. However， when serum cyclosporine trough level between 100 and 150 ng/mL， the clinical efficacy was improved and the platelet count was above 100×10⁹/L. The patient was followed up for more than 6 months， and no recurrence of disease was found. Cyclosporine combined with low-dose glucocorticoid is safe and effective for SLE associated ITP. Therapeutic drug monitoring is a powerful tool for improving clinical efficacy and ensuring drug safety.