The present invention discloses a stem cell culture medium and its applications as well as a stem cell culture method. The said stem cell culture medium contains no serum. The said stem cell culture medium contains amino acids, vitamins, salts, lipids, cytokines and protein polypeptides. The said stem cell culture medium is suitable for rapid culture of stem cells derived from human and mammalian tissues, including but not limited to, adipose mesenchymal stem cells, bone marrow mesenchymal stem cells and umbilical cord blood stem cells. The said culture medium can increase the proliferation speed of the stem cells 3-5 times, without any affects on their differentiation potentials. Comparing the said stem cell culture medium to a routine culture medium, the said culture medium is not only able to proliferate stem cells derived from different sources more rapidly and achieve more proliferation generations, but also keep their differentiation potentials well.