Hematopoietic stem cell microtransplantation,as a new treatment method,plays an increasingly important role in the treatment of malignant hematological diseases,especially elderly acute myeloid leukemia(AML).This article describes the background of the birth of microtransplantation,the proposed concept and implantation mode,and summarizes and expects that microtransplantation technology will play a greater role in the fields of malignant blood diseases,solid tumors and infectious diseases in combination with the current research situation of microtransplantation.