An analytical method was developed for the simultaneous determination of 12 banned dyes（basic orange 2，basic orange 21，basic orange 22，dimethyl yellow，ethyl yellow，sudan orange G，auramine O，solvent yellow 124，orangeⅡsodium salt，metanil yellow，acid yellow 11 and allzarin yellow R） in soy products by ultra performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS）.Soy products samples were extracted using acetonitrile acidified with acetic acid.After frozen for 2 h under-20 ℃，the extracts were centrifuged to reduce lipids and other related interference.The target compounds were separated on an ACQUITY UPLC- BEH C18 column by means of a binary mobile phase gradient with water containing 0.1% ammonium hydroxide formic acid and acetonitrile for 4 dyes（orangeⅡsodium salt，metanil yellow,acid yellow 11 and allzarin yellow R） and 0.1% formic acid and acetonitrile for the other eight compounds.Mass spectrometric acquisition was carried out by means of multiple reaction monitoing（MRM） under negative ionization mode for 4 dyes and positive mode for the rest of target compounds，respectively.As a result，quantitation limits of 12 dyes in soy products samples were in the range of 0.2-10.0 μg/kg.Mean recoveries at three spiked levels ranged from 76.2% to 122.0%，and the relative standard deviations（RSDs）were between 1.1% and 7.4%，which complied with the regulations for the determination of trace contaminants residues in food matrix.Simultaneous extraction and purification of 12 dyes in soy products matrix was achieved upon the established method which could be applied in the routine detection of illegally additive dyes in soy products due to its simplicity and high sensitivity.