Background Lupus cystitis, a severe complication of systemic lupus erythematosus (SLE), presents considerable treatment challenges. Purpose This case report describes the use of telitacicept in treating severe SLE with lupus cystitis. Research Design A single patient with lupus cystitis. Study Sample A patient with symptoms including frequent urination, urgency, and acute urinary retention. Data Collection and Analysis Initial treatments included corticosteroid pulse therapy, immunoglobulin, and cyclophosphamide, which improved laboratory indicators but failed to alleviate symptoms of urinary retention. The patient was then treated with telitacicept. Results Significant alleviation of urinary retention was observed shortly after incorporating telitacicept into the treatment regimen. The patient's condition remained stable with no relapse during the subsequent 10 months of follow-up. Conclusions This case highlights the therapeutic potential of telitacicept for SLE patients who are unresponsive to conventional therapies, particularly those with severe manifestations such as lupus cystitis.