Abstract: To achieve the high-value utilization of Scomberomorus niphonius head, anti-photoaging peptides were prepared by enzymatic hydrolysis and the enzymatic hydrolysis process was optimized by response surface methodology. The enzymatic hydrolysate by compound protease hydrolysis obtained under the optimal process conditions was subjected to ultrafiltration to obtain three different ultrafiltration fractions (>3 kDa、1~3 kDa and<1 kDa). The anti-photoaging effects of these three different ultrafiltration fractions were evaluated, and the ultrafiltration fraction with the best effect (SP-3) was selected. Using normal human skin fibroblasts（NHDF and B16F10 melanoma cells exposed to UVB as research subjects, the effects of SP-3 on type I collagen level and melanin production as well as their possible mechanisms were studied. The results showed that the optimal enzymatic hydrolysis process was as follows: the enzymatic hydrolysis temperature was 56.96 ℃, the added amount of the compound protease was 1828.47 U/g, and the enzymatic hydrolysis time was 5.27 h. The process parameters were adjusted based on actual operation, and the verification showed that the percentage of SA-β-gal positive cells was 45.35%. Through active screening, the molecular weight of the optimal component SP-3 for anti-photoaging was found to be less than 1 kDa. The mechanism that SP-3 exerted the anti-photoaging effect was studied. It was discovered that SP-3 could down-regulate the expressions of matrix metalloproteinase, reduce the activity and expressions of tyrosinase and related proteins, thereby increasing the level of type I collagen and decreasing melanin production in skin cells which may be related to the inhibition of (JNK, p38)/c-Jun and PKA/CREB/MITF signaling pathways. In summary, SP-3 could exert anti-photoaging effect by increasing type I collagen level and reducing melanin production in UVB-exposed skin cells.