The invention provides a
leukemia bacteriophage single-chain
antibody library, which uses phasmid pCANTA-5E as a carrier, has storage capacity of 1.5*10<9>, and has excellent diversity in proving of
DNA (deoxyribonucleic acid) sequencing. A
leukemia cell specific completely humanized single-chain
antibody can be obtained conveniently in multiple screenings by using a specific
leukemia related
antigen as a target through a
bacteriophage representation technology from the completely humanized single-chain
antibody library. The antibody
library provided by the invention has high storage capacity and excellent diversity, and comprises a combination of complete humanized single-chain antibodies; and a single-chain antibody is formed by connection of a
heavy chain variable region VH and a light chain variable region VL through a connecting
peptide (GGGGS)3, and contains a complete
antigen-
binding site. The method has the advantages of strong
operability and high storage capacity, and can be used for conveniently screening the leukemia
cell specific completely humanized single-chain antibody; and the completely humanized single-chain antibody can be used for preparing a target medicament, which is used for treating leukemia.