A method of high performance liquid chromatography-tandem mass spectrometry（HPLC-MS/MS） was established for the determination of migration of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide（DOPO）in plastic polymers.The migration regularity of the analyte in different simulants,temperatures and times were studied.Samples were soaked with the food simulants according to（EU）2017/752.The water based simulated sample was directly filtered,and the olive oil simulated sample was extracted with acetonitrile solution containing 38% methanol.The samples were separated on a C18 column with methanol-2 mmol/L ammonium acetate containing 0.1% formic acid as mobile phases,and analyzed under multiple reaction monitoring mode.The quantitation limits of the method for water based simulant（3% acetic acid,10% alcohol,50% alcohol）and olive oil simulant were 0.10 ng/mL and 1.0 ng/g,respectively.The spiked recoveries ranged from 85.3% to 110% with relative standard deviations（RSD）not more than 7.3%.This method was rapid,precise and convenient,and was appropriate for the determination of DOPO migration in plastic polymers.