Lactobacillus plantarum and Saccharomyces cerevisiae were used to prepare two kinds of dayrose fermentation broth. By monitoring the scavenging capacity of DPPH radical, hydroxyl radical and total antioxidant capacity of the two fermentation broth, it was found that the antioxidant capacity of the fermentation broth was stronger than that of the aqueous extract (blank control). At the cellular level, both fermentation broth showed repair effects on UVB-induced injury cells, and compared to the cell model group after UVB irradiation, the activities of collagen type ⅰ (COL-1) and catalase (CAT) were increased. In the experiments of tyrosinase activity inhibition,the daylily fermentation broth showed good whitening effect compared with the water extract. According to the expression levels of inflammatory factors IL-6, TNF-a and COX-2 in HaCaT cells, the expression level of inflammatory factors in the sample group was significantly lower than that in the model group, indicating that the anti-inflammatory ability of daylily fermentation broth was greater than that of water extract. The results of chick chorioallantoic membrane test (HET-CAM) showed that there was no bleeding phenomenon before and after treatment, and the daylily fermentation broth was not irritating. Finally, it was concluded that the two kinds of daylily fermentation can be used as natural plant raw materials for cosmetics, which have strong antioxidant, anti-inflammatory and whitening functions on the skin, and also have good human safety.