Abstract: The homogenized powder sample of dried chili （2.50 g） was taken, and 10 mL of 0.1% （volume fraction, the same below） formic acid solution was added. The mixture was vortexed and settled for 10 min, and 10 mL of n-hexane-saturated acetonitrile solution was added. The mixture was oscillated for 5 min, and the QuEChERS extraction salt packet （containing 4 g of anhydrous magnesium sulfate, 1 g of sodium chloride, 0.5 g of disodium citrate sesquihydrate, and 1 g of sodium citrate） was added. The mixture was shaken rapidly and oscillated for 10 min. After centrifugation for 5 min, 1.0 mL of the supernatant was taken and placed into a centrifuge tube containing 150 mg of anhydrous magnesium sulfate, 50 mg of N-propylethylenediamine, 50 mg of octadecylsilane-bonded silica gel, and 20 mg of graphitized carbon black. The mixture was vortexed for 1 min and centrifuged for 5 min. Subsequently, 0.5 mL of the supernatant was taken and 0.5 mL of water was added. The solution was homogenized and passed through 0.22 μm filter membrane. The 21 succinate dehydrogenase inhibitor （SDHI） fungicides in the filtrate were determined by high performance liquid chromatography-tandem mass spectrometry using Thermo Accucore-aQ column as the stationary phase, and a mixture of methanol and 5 mmol·L⁻¹ ammonium formate solution containing 0.1% formic acid at different volume ratios as the mobile phase for gradient elution. The electrospray ion （ESI） source was used for mass spectrometry analysis in the multiple reaction monitoring （MRM） mode, and the matrix matching method was used for quantification. As shown by the results, linear relationships between the values of the corresponding quantitative daughter ion peak area and mass concentrations of 21 SDHI fungicides were found in the range of 0.001‒0.5 mg·L⁻¹, with the same lower limits of determination （10S/N） of 0.01 mg·kg⁻¹. Test for recovery was made by the standard addition method, giving results in the range of 79.0%‒108%, with RSDs （n=6） of the determined values in the range of 0.53%‒14%. This method was applied to the analysis of 20 batches of dried chili samples, and 21 SDHI fungicides were not detected.