The invention relates to a technical method for differentiating human skin stem cells in vitro into primordial germ cells, which comprises the following steps: separating the human skin stem cells by utilizing a mechanical method; culturing the human skin stem cells in vitro; performing differentiation by utilizing a method of forming embryoid bodies in vitro by the human skin stem cells; after differentiation, performing induction in vitro for 14 days by using cell factors of bone morphogenetic protein-4, a stem cell growth factor, an epidermal growth factor, a basic fibroblast growth factor and the like, so that a plurality of primordial germ cell-like cells capable of expressing genes of early germ cells can be obtained; and then performing induction by adopting follicular fluid of a pig. By the method disclosed by the invention, the specific molecular marker expressed primordial germ cell-like cells of which the morphology is like that of normal primordial germ cells in a human body is obtained; and expressions Stra8 (stimulate by retinoic acid) and Dazl (Deleted in Azoospermia-Like) of the primordial germ cell-like cells obtained by induction in vitro are subjected to cell fluorescence analysis, and the primordial germ cell-like cells can realize early meiosis.