Recombinant Anti-B cell lymphoma BCL1 Idiotype x Anti-CD3 Bispecific Antibody (Fab-Fv) is designed to be expressed as two polypeptide chains. The heavy chain Fd fragment and light chain of an anti-B cell lymphoma BCL1 Idiotype antibody are fused with the VL and VH domains of an anti-CD3 antibody respectively. It can form natural in vivo heterodimerization. This BsAb can block cell adhesion. It is designed for the research of B cell lymphoma therapy.