The invention discloses a mesenchymal stem cell serum-free culture medium. The culture medium takes an L-DMEM, DMEM-F12 or alpha-MEM culture medium as a basic culture medium and also includes the following addition components: fibronectin, laminin, transferrin, trypsin, aprotinin, growth hormone, insulin, hydrocortisone, dexamethasone, bFGF, EGF, B27, IGF-I, IGF-II, choline, linoleic acid, sodium selenite, phosphorylethanolamine, glutathione, vitamin C, vitamin E, vitamin B12 and biotin. The culture medium has the advantages of defined composition and controllable quality, and mesenchymal stem cells cultured by the culture medium grow normal; and after multiple passages, the 'dryness' of the mesenchymal stem cells and the ability of the mesenchymal stem cells to be differentiated into osteoblasts, chondrocytes, adipocytes, neurons and other types of cells are still kept.