A new method for rapid screening for and identification of 11 foodborne stimulants and five alkaloids in hot pot soup base seasoning by ultra-high performance liquid chromatography-quadrupole-time of flight mass spectrometry (UPLC-Q-TOF/MS) was developed. The analytes from samples were extracted with 80% aqueous acetonitrile, cleaned up on a PRiME HLB column, and separated on a Kinetex F5 column prior to qualitative screening and quantitative analysis in the high-resolution scanning mode using multiple reaction monitoring (MRM). The relative deviations of the exact mass numbers of the 16 compounds were less than 5.0 × 10^-6, and the linearity of the calibration curves was good with correlation coefficient (R²) greater than 0.9970. The recoveries of the analytes were 75.2%–105.4%, with relative standard deviation (RSD) of 1.3%–7.4% (n = 6). The limit of detection (LOD) was 0.05–1.0 µg/kg, and the limit of quantitation (LOQ) was 0.10–2.0 µg/kg. The developed method is simple, rapid, accurate, and practical.