In this study, a method for the simultaneous determination of 20 pyrazines in Baijiu was established by direct injection (DI) combined with gas chromatography-tandem mass spectrometry (GC-MS/MS), and the pyrazines in 10 brands of Baijiu with different flavors were determined by the method. The developed method showed good linearity in the concentration range of 0.01-10.00 mg/L with determination coefficients (R²) in the range of 0.9983-0.9997, the limits of detection (LOD) were in the range of 0.16 × 10^-3-3.25 × 10^-3 mg/L, the recovery rates at different spiked concentrations ranged from 81.26% to 113.13%, and the intra-day and inter-day relative standard deviations (RSDs) varied between 1.42% and 4.98%. Among the ten types, pyrazines were the most abundant in Jiang-flavor Baijiu with concentrations ranging from 2.63 to 16.88 mg/L, followed by Zhima-flavor and nong Jiang-flavor Baijiu. This method has higher accuracy and sensitivity than GC-MS, and is suitable for the analysis of pyrazines in different aroma types of Baijiu.