To determine anionic impurities in energetic plasticizer triethylene glycol dinitrate (TEGDN) , the anions in TEGDN were qualitatively and quantitatively analyzed by a preparative liquid chromatography-ion chromatography method. The effect of different mobile phase ratio, injection volume and collection time on the effect of separation and collection of anionic impurities in TEGDN in preparative liquid chromatographic experiments, and the effect of eluent system and eluent flow rate on the separation effect of anions in ion chromatographic experiments were investigated. Results show that the preparative liquid chromatographic conditions after optimization are: Eclipse XDB-C18 chromatographic column (250 mm×9.4 mm, 5.0 μm); mobile phase, V_methanol∶V_water=50∶50; flow rate, 1.5 mL·min^-1; detection wavelength, 210 nm; column temperature, 30 ℃ ; injection volume, 0.25 mL. The ion chromatographic conditions after optimization are: Metrosep A Supp 5 anion analysis column (250 mm× 4.0 mm, 5.0 μm); 3.2 mmol·L^-1 Na₂CO₃ / 1.0 mmol·L^-1 NaHCO₃ solution as eluent ; flow rate, 0.7 mL·min^-1 ; suppression conductivity detector ; column temperature, 40 ℃ ; injection volume, 20 μL. Under the optimized preparative liquid chromatographic conditions, anionic impurities in TEGDN are effectively separated and collected. Under the optimized ion chromatographic conditions, the linearity of the anions is good, the linear correlation coefficients are greater than 0.999 ; the detection limits of anions are 0.0025-0.0100 μg·mL^-1. The relative standard deviations of the precision test (n=6) and the repeatability test (n=6) are less than 2.0%, the average recoveries of anions are 95.5%-103.5%. The method has high sensitivity and good reproducibility, can be used for the determination of the anionic impurities in TEGDN.