By studying the influence of various experimental conditions on the experimental results during the reaction of ferrocene and hydroperoxide, a method for detecting the peroxide value of vegetable oils has been established. The experimental results showed that the best experimental conditions were mixing 1 mL of oil sample with 1 mL of ferrocene standard solution, 0.1 mL formic acid was added, then add isopropanol to 5 mL, heating temperature was 60 ℃, heating time was 40 min, and detection wavelength was 310 nm. The standard curve of this method was y=0.175 2x+0.220 2 （R²=0.999 6）, the LOD was 0.08 mmol/L, the LOQ was 0.26 mmol/L, the recovery rate was 98.16%~100.03%. The results showed that the ferrocene method and the iodometric titration method have a good correlation. The ferrocene method can be used to detect peroxide value.