The dispersion liquid-liquid microextraction assisted by pasteurized dropper（PTD-DLLME） combined with ultra-high performance liquid chromatography-tandem mass spectrometry（UPLC-MS/MS） method was established for the simultaneous determination of 7 neonicotinoid pesticides in environmental water. In the experiment，a pasteurized dropper was used as the extractor，acetonitrile with low density and low toxicity was used as the extractant，and acetone was used as the dispersant for the first time. The separation was performed on a BEH C

18

column（2.1 mm×50 mm，1.7 μm） by gradient elution，with 0.01% formic acid aqueous solution（containing 2 mmol/L ammonium formate） and 0.01% formic acid acetonitrile solution（containing 2 mmol/L ammonium formate） as the mobile phases. After optimization of the gradient elutio

n procedures and mass spectrometric conditions，chromatographic separation and feature recognition of the 7 neonicotinoid pesticides were obtained. Moreover，the optimal extraction conditions were determined as follows：sampling volume was 10 mL，extraction salt was 1 g NaCl and 4 g MgSO

4

，extractant was acetonitrile（800 μL），and dispersant was acetone（400 μL），which was confirmed by the best extraction efficiency in the sample pretreatment. Analytes were scanned in positive ion mode by electrospray ionization source（ESI） under multiple reaction monitoring（MRM） mode，qualitated by retention time and characteristic ion，and quantitated by external standard method. Under the optimal conditions，the linear relationship of target compounds were good in the range of 0.05-100 μg/L with the correlation coefficients（

r

2

） not less than 0.996. The limits of detection（LOD） were in the range of 0.02-0.1 μg/L，while the limits of quantitation（LOQ） were in the range of 0.05-0.2 μg/L，and the enrichment ratio was 10 times. At the spiked levels of 1，2 and 10 times LOQ，the recoveries of the analytes ranged from 75.3% to116%，and the relative standard deviations of intraday（Intra-RSDs，

n

=6） were 2.7%-8.2% and that of interday（Inter-RSDs，

n

=3） were 3.1%-10% . The matrix effects of the 7 neonicotinoid pesticides ranged from -0.18% to 6.66%. The established method was applied to 20 batches of environmental water samples，in which imidacloprid and thiacloprid were detected in one river water sample，but their concentrations were below LOQ. This study indicated that PTD-DLLME combined with UPLC-MS/MS is an effective analytical method to detect 7 neonicotinoid pesticides in environmental water. The method is easy to operate，has a good enrichment effect，and offers stable recovery，environment friendly，and low cost，providing a new solution for the detection of neonicotinoid pesticides in environmental water samples.