Given that Telitacicept and low dose IL2 have been widespreadly applied in the treatment of systemic lupus erythematosus, this study designed a randomised, single center, prospective study to investigate the effects and safety of combined utilization of Telitacicept and low dose IL-2. 160mg Telitacicept and 1 million IU IL2 were regularly administered according to different circumstances. Then, the investigators evaluated the improvement of clinical and laboratory indexes and monitored the changes of immune cell subsets and cytokines.