To address the challenges of low extraction efficiency of carotenoids from yellow peach, this study investigated the effects of ultrafine grinding (UG) and/or ultra-high pressure homogenization (UHPH) pretreatment on carotenoid extraction yield and antioxidant activity. Key parameters including solid-to-liquid ratio, UG rotation speed, UHPH pressure, and number of homogenization cycles were systematically optimized. The optimal extraction conditions were determined as follows: solid-to-liquid ratio of 1:1 (m/m), UG rotation speed of 3000 r·min?1, UHPH pressure of 100 MPa, and two homogenization cycles. Under these conditions, the total carotenoid content reached 147.23 ± 1.97 μg·g?1, representing a 41% increase compared to the conventional treatment group (103.98 ± 0.41 μg·g?1). Among the identified carotenoid monomers, phytoene (90.86 ± 21.19 μg·g?1), lycopene (33.76 ± 0.81 μg·g?1), and β-carotene (5.00 ± 0.74 μg·g?1) were the most abundant.The antioxidant activity of carotenoids extracted using different processing methods was comprehensively evaluated using both radical-based assays and a cellular model. Radical scavenging assays showed that carotenoids extracted via the combined UG-UHPH treatment achieved ABTS and DPPH radical scavenging rates of 86.23% and 87.71%, respectively, which were 18.16% and 19.26% higher than those of the conventional treatment group. Using an oxidative stress model in HepG2 cells, the malondialdehyde (MDA) content in cells treated with the UG-UHPH-extracted carotenoids was 2.17 ± 0.05 nmol·mg?1, equivalent to only 52.16% of that in the model group. Furthermore, the activities of catalase (CAT) and superoxide dismutase (SOD) were 1.28 and 1.32 times higher than those in the model group, respectively.In conclusion, the combined UG-UHPH technology significantly improved both the extraction efficiency and the antioxidant activity of carotenoids from yellow peach, providing a theoretical basis for the application of this technology in the extraction of bioactive components from fruits and vegetables.