• We isolated and screened the Saccharomycopsis fibuligera strain SF-1 with high protein production from rice wine koji. • HPLC analysis showed that the molecular weight of SF-1-ECPs was less than 2000 Da, accounting for 22.28%. • The extracted SF-1-ECPs have strong antioxidant properties. • The antioxidant capacity of HSF and the enzymatic activity of MMP-1 were enhanced and weakened by SF-1-ECPs, respectively. • It was found that SF-1-ECPs improves the antioxidant capacity of HSF mainly by improving Nrf2/Keap1/Mafk signal transduction. Saccharomycopsis fibuligera is recognized as a food-based yeast which is widely used in food and drugs due to its high yield characteristics of extracellular enzymes. In this study, the extracellular proteins of S. fibuligera (SF-1-ECPs) are analyzed by HPLC, finding that 22.24% of the molecular weight of SF-1-ECPs is less than 2000 Da, and biochemical experiments, cell and cell molecular experiments are conducted to explore the significance of SF-1-ECPs in cosmetics. The results show that SF-1-ECPs can enhance antioxidant enzyme activity and mRNA expression within cells by using the Nrf2/Keap1/Mafk pathway to eliminate intracellular reactive oxygen, thereby protecting human skin fibroblasts from UVA-induced oxidative stress. They can also protect COL-I degradation caused by the increase of MMP-1 and thus delay skin aging.