The present invention provides a humanized anti-human CD34 antibody and the preparation method thereof. The humanized anti-human CD34 antibody retains the affinity and specificity of its original murine-derived antibody. The antibody can be conjugated with magnetic nano materials to prepare immunomagnetic beads to screen marrow hemopoietic stem cells. It can effectively reduce the incidence rate of HAMA and improve the security of clinical transplantation of hemopoietic stem cells and can be used in treatment of certain malignant hematologic diseases and solid tumors.
