The work aims to study the HS-GC/MS for 4 kinds of harmful monomers (1,3-butadiene, acrylonitrile, ethylbenzene, styrene) in plastic packaging materials for food. After crushed with liquid nitrogen and heated by headspace, the plastic packaging materials were tested by mass spectrometer detector with the headspace air. The qualitative and quantitative ions of the target were obtained by scanning the reference material, and the target was qualitatively and quantitatively determined by the standard curve. The calibration curve of each monomer showed good linear relationship in the following concentrations: 1,3-butadiene, acrylonitrile: 0.02~2 mg/mL; ethylbenzene, styrene: 0.1~10 mg/mL. The detection limit of the method was 0.05, 0.05, 0.02 and 0.02 mg/kg, respectively. The recovery test of 4 monomers was conducted. The recovery rates of this method varied from 94.42% to 106.07% with relative standard deviations (RSDs) ranging from 2.76%~5.91%. The HS-GC/MS for 4 kinds of harmful monomers in plastic packaging materials for food is established. The proposed method has lower detection limit and less time in sample pretreatment, and it can serve as a guidance for rapid detection of harmful monomer in plastic materials for food packaging.