An analytical method was developed for the simultaneous determination of 11 banned azo=dyes （Sudan red Ⅰ，Sudan red Ⅱ，Sudan red Ⅲ，Sudan red Ⅳ，Sudan red 7B，Sudan red G，Sudan yellow，Sudan orange G，Sudan blue Ⅱ，toluidine red，para red） and rhodamine B in seasoning oil based on gel permeation chromatography followed by ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）.The seasoning oil samples were extracted with cyclohexane-ethyl acetate（1∶1），and then purified by gel permeation chromatography to remove the high molecular weight of interferences（e.g.fat，oil and natural pigments）.Twelve target compounds were separated on an ACQUITY UPLC- BEH C18 column with 0.1% formic acid and acetonitrile as mobile phase by gradient elution，and detected by MS/MS under positive mode with multiple reaction monitoring（MRM）.Good linearities for 12 dyes were achieved over the range of 1-50 μg/L.The quantitation limits of 12 dyes in seasoning oil samples were in the range of 0.2-2.5 μg/kg.The mean recoveries at three spiked level（5，20，40 μg/L） ranged from 54% to 125%， with relative standard deviations（RSDs） of 2.5%-17.2%.The method was used to analyze 35 seasoning oil samples taken randomly from the local market，and rhodamine B was found in 2 of the samples.The established method could be applied in the simultaneous extraction and purification of 11 azo-dyes and rhodamine B in seasoning oil matrix，and is suitable for the routine detection of illegally additive dyes in seasoning oil due to its simplicity and high sensitivity.