Objective　To explore the clinical characteristics, diagnosis and treatment of systemic lupus erythematosus (SLE) with thrombotic thrombocytopenic purpura (TTP). Method　The clinical data of SLE combined with TTP in a child were analyzed retrospectively, and the related literature was reviewed. Results　A 13-year-old girl who was presented with onset of nephrotic syndrome was diagnosed with severe SLE and lupus nephritis. Headache, thrombocytopenia, anemia, acute kidney injury and fever reappeared after initial treatment and improvement. The ratio of broken red blood cells in the blood smear was 2%, and TTP was diagnosed. After comprehensive treatment such as high dose of hormones, plasma exchange, and application of immunosuppressive agents, her condition was relieved. Conclusion　SLE with TTP is relatively rare and has a high mortality. Early recognition and appropriate treatment can improve the prognosis.