As a therapeutic treatment for systemic lupus erythematosus (SLE), Belimumab reduces disease relapses and minimizes organ damage. Clinical practice, however, shows that the treatment is ineffective for a number of patients. Treatments for such cases are still lacking. As a biologic agent that targets both BLys and APRIL, Telitacicept inhibits both B cells and plasma cells. This case report describes a 35-year-old female with lupus nephritis (LN) who had previously undergone 10 cycles of Belimumab treatment but remained poorly controlled. Despite this, her condition improved significantly after switching to Telitacicept. This is the first report on the efficacy of Telitacicept in an SLE patient with suboptimal response to Belimumab. Telitacicept's role in this scenario needs more investigation and attention.