A fast method of separating and detecting the polar compounds in frying oils by preparative FLASH chromatography was established in this study. Applying the EOPC type medium pressure liquid preparative chromatography system as hardware platform and EOPC-specified FLASH column as separation & preparation column, petroleum etherdiethyl ether(8713) as elution solvent, 25 min/min as flow speed, we found polar components(PCs) and non-polar components(non-PCs) in frying oils could be separated properly when elution time of non-PCs was 11min. Separation speed was fast, as the time took by preparative FLASH chromatography was only 41 min, repeatability RSDs of preparative FLASH chromatography were no more than 5%, which were both better than that of traditional manual column chromatography. The results acquired by preparative FLASH chromatography were almost equal to those acquired by traditional manual column chromatography, as their relative deviations were within ±6% according to the results acquired by traditional manual column chromatography.