The invention discloses a composition of yeast fermentation extracts. The composition is prepared from 75 to 95 percent of a bifida yeast fermentation product cell-lysing substance and the balance ofa poly-yeast compound and a perigord truffle yeast extract, wherein the content of the perigord truffle yeast extract is 0.01 to 0.5 percent. The invention also discloses application of the composition of the yeast fermentation extracts in cosmetics. By combining the effects of ultraviolet damage resisting, purifying and repairing, oxidation resisting and crease resisting of the bifida yeast fermentation product cell-lysing substance and the perigord truffle extract and through a synergistic skin care effect with poly-yeast, multiple care effects on skin and safe and long-term effective care can be realized.