Taking ethyl acetate as extraction solvent with low toxicity, good stability, and low cost, and through the combined extraction of vortex 2 min and microwave extraction 20 min to extract the effective substances, 12 kinds of preservatives were separated and determined（propionic acid, dimethyl fumarate, sorbic acid, benzoic acid, sehydroacetic acid, methylparaben, ethylparaben, propylparaben, butyl paraben, isopropyl paraben, isobutylpareben, heptylparaben）in food by gas chromatography. The recovery is 92.1%～108.3%, the average recovery rate is 98.5%, and the standard deviation recovery is 3.0%. The test results are accurate and reliable. Compares to the standard gas chromatographic method and liquid chromatography method, the result of the deviation in line with the requirements of methodology is reliable.