Abstract: 【Objective】 To compared the effects of two pretreatment methods on the determination of DIMBOA in Helicoverpa armigera, and establish an UPLC-MS/MS method for the determination of DIMBOA in H. armigera. 【Methods】 The samples of H. armigera were extracted by methanol vortex oscillation and ultrasonic wave and the content of DIMBOA was determined by Waters UPLC-MS/MS (Xevo TQS mass spectrometry). The chromatographic column was BEH C18, the mobile phase was methanol- pure water (containing 0.5% glacial acetic acid) gradient elution, and the flow rate was 0.3 mL/min. 【Results】 At concentrations of 5 and 50 μg/L, the addition recovery rate of methanol ultrasonic extraction method was the best, the average addition recovery rates were 84.26% and 96.78%, respectively, and the limit of quantity was 5 μg/L. 【Conclusion】 The accuracy, precision and addition recovery of methanol ultrasonic extraction method meet the requirements of compound residue analysis.