Objective To establish the first method for the simultaneous determination of 11 p-phenylenediamine antioxidants （PPDs） and their oxidation products in milk by solid-phase extraction （SPE） coupled with ultra performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS）.Methods A 2.00 g milk sample was weighed， freeze-dried， and extracted with 10 mL of acetonitrile. The mixture was shaken， then centrifuged at low temperature. The supernatant was purified using an Oasis HLB solid-phase extraction column. The combined sample and purified liquid were evaporated under nitrogen and resuspended for injection and analysis. Chromatographic separation was performed using a gradient elution with a mobile phase of 0.1% formic acid aqueous solution and acetonitrile. The analysis was carried out on a WATERS ACQUITY BEH C18 column （2.1 mm×100 mm， 1.7 μm）. Detection was conducted in positive ion electrospray ionization （ESI⁺） multiple reaction monitoring （MRM） mode， and quantification was achieved using the internal standard method.Results The correlation coefficients （R2） for all 11 PPDs and their oxidation products were greater than 0.990 within the concentration range of 0.1-50 μg/L. The method detection limits ranged from 0.004 to 0.152 μg/kg， and the quantification limits ranged from 0.013 to 0.507 μg/kg. Recovery rates for three different spiked concentrations ranged from 84.4% to 121.9%， with good intra-day and inter-day precision （RSD<14%）. When applied to 28 milk samples from different countries and regions， the detection rate for 6PPD was the highest， with positive concentrations ranging from 0.05 to 2.27 μg/kg. The detection rate for DTPD was 39%， with positive concentrations ranging from 0.07 to 0.79 μg/kg， and only two samples had 6PPD-Q concentrations above the limit of quantification.Conclusion This method demonstrates excellent sensitivity， accuracy， and precision， making it suitable for detecting p-phenylenediamine-based antioxidants and their oxidation products in milk samples.