The invention discloses an extraction and separation method for mesenchymal stem cells (MSCs), and the extraction and separation method is used for local-anesthesia downlink bone marrow puncture. The method comprises the following steps: totally extracting 130ml of bone marrow from two sides by use of a 20ml dry and sterile syringe, injecting the bone marrow into a heparin blood bag which is prepared in advance, and rapidly delivering the heparin blood bag to a laboratory; adding sodium citrate used as an anticoagulant into a special reagent for stem cell extraction, and extracting about 0.8ml stem cell suspension by use of a stem cell separation and extraction technology; and adding the stem cell suspension into a gentamicin brine so as to dilute the stem cell suspension to 5ml. According to the method, firstly the MSCs can be extracted from bone marrow of a patient; secondly, the MSCs can be rapidly cultured and amplified in vitro, and can be subjected to directional differentiation towards nerve cells; furthermore, the MSCs can be input back into the body of the patient, and can be integrated in a host central nervous system and exist for a long time; the risks of the method are less than those of allotransplantation, the ethical issues are rarely involved, and BMSCs have favorable prospect and development potential in the aspect of clinic treatment.