The invention discloses an extraction method of a micromolecular sheep placenta extract and application of the micromolecular sheep placenta extract in the field of skin-care products, belonging to the technical field of biology. The extraction method disclosed by the invention comprises the following steps of obtaining a lot of sheep pregnant in the same period by adopting synchronization of estrus, taking out sheep fetus after 85-100 days through an operation method to obtain body homogenate, carrying out repetitive freeze-thawing and splitting cells, degenerating at high temperature, sterilizing, precipitating hybrid protein, carrying out 30 KD ultrafiltration after centrifuging at high speed so as to remove toxic and harmful components and impurities, such as macromolecular hybrid protein, bacteria and endogenous virus, so as to obtain a pure micromolecular sheep placenta extract product, and carrying out ultrafiltration and concentration of the micromolecular sheep placenta extract product by using a 1 KD ultrafiltration component. The micromolecular sheep placenta extract disclosed by the invention can be widely used in the fields of skin-care products, beauty products, wound healing products, health-care products, scientific searches and the like; the extraction method disclosed by the invention provides a novel important way for producing the sheep placenta extract; furthermore, the compositions of the micromolecular sheep placenta extract are authenticated for the first time, and thus, theoretical foundation is provided for scientifically using the sheep placenta extract.