Gold nanosol with good stability and high SERS activity was prepared under the light wave irradiation, with triethanolamine as reducing agent. In the acid medium, the oxidized product of scorbic acid (SA) by H₂O₂, malondialdehyde, react with thiobarbituric acid (TBA) to produce 3,5,5-trimethyloxazole-2,4-dione (trimethadione, TMD) that exhibited strong surface-enhanced Raman scattering (SERS) effect at 1280 cm⁻¹ in the as-prepared gold nanosol substrate containing enhancement reagent of AlCl₃. Under the chosen conditions, the SERS intensity at 1280 cm⁻¹was linear to the SA concentration in the linear range of 0.0066–1.59 μg/mL, with a detection limit of 3.2 ng/mL. This SERS method has been applied to the quantitative analysis of SA in real samples with advantages of high sensitivity, good selectivity and simple operation.