Objective: This study focuses on exploring a more effective method of tetrahydrocurcumin synthesis. Methods: With vanillin and acethylacetone as starting materials, curcumin was prepared by Claisen condensation reaction under the condition of alkali, and then a hydrogenation reaction was conducted with palladium catalysis to obtain tetrahydrocurcumin. Its structural identification was confirmed by Ultraviolet and Visible Spectrophotometry (UV-VIS), Infrared Spectroscopy (IR) and Nuclear Magnetic Resonance Spectroscopy (¹H-NMR, ¹³C-NMR). The antioxidant activity was evaluated by DPPH radical scavenging capacity, ABTS radical scavenging capacity and total antioxidant capacity. Results: The results showed that the total yield of this synthesis was 45.70%, and the purity was 97.68%. on the DPPH radical scavenging activity \[IC₅₀=(74.33±0.003) mg/L\] of tetrahydrocurcumin was significantly higher than that of BHT; its ABTS radical scavenging activity \[IC₅₀=(17.15±0.004) mg/L\] was significantly higher than that of V_C, and the total antioxidant capacity and ferric reducing ability were stronger than BHT and V_C. Conclusion: Compared with existing preparation methods, this method is more efficient which inclining a potential price advantage. The antioxidant capacity of tetrahydrocurcumin is mainly embodied in free radical scavenging and chemical reduction, showing a potential application prospect.