The invention relates to the technical field of induced differentiation of cells and in particular relates to a serum-free culture medium capable of improving transformation from mononuclear cells tomultipotent cells. The serum-free culture medium is prepared from the following substances: inorganic salt, organic matters, amino acid, amino acid salt, phytagglutinin, insulin, a carbon source, a cell growth factor, vitamin and an antioxidant, protein, trace elements and a pH (Potential of Hydrogen) value indicator. According to the serum-free culture medium capable of improving the transformation from the mononuclear cells to the multipotent cells, the transformation from the mononuclear cells to the multipotent cells including vascular endothelial cells and the like is improved under the induction of various endothelial growth factors, and experiment data and a theoretical foundation are provided for more reasonably utilizing the mononuclear cells to treat clinically.