Recombinant Anti-albumin x Anti-IL-6R Bispecific Antibody (Bi-nanobody) is designed to be expressed as a VHH from anti-albumin antibody variable domains fused with a VHH from an anti-IL-6R antibody variable domains. It contains a His-tag at the C/N terminus for affinity purification. The BsAb exits as monomer in reducing and non-reducing conditions. This BsAb can act as PK-modulated receptor antagonist. It is designed for the research of Systemic lupus erythematosus (SLE); Rheumatoid arthritis (RA).