A modified QuEChERS（quick，easy,cheap,effective,rugged,safe） method based on multi-walled carbon nanotubes（MWCNTs） was established for the simultaneous determination of 145 pesticide residues in limnetic products by gas chromatography- quadrupole time of flight mass spectrometry（GC-QTOF/MS）.The samples were extracted with water and acetonitrile，purified by QuEChERS with MWCNTs，determined by GC-QTOF/MS.The quantification analysis was performed with the external standard calibration.The extraction conditions，type and amount of adsorbents，acquisition rate and extraction window of GC-QTOF/MS were optimized.Under the optimal conditions，the results indicated that the calibration curves were linear（r2>0.98） in the range of 5-200μg/kg.The recoveries for 145 pesticides were in the range of 69.4%-114.2% at three spiked levels of 10，20，100μg/kg，with relative standard deviations（RSD，n=6） of 2.2%-13.8%.The limits of quantitation were in the range of 1.1-40.0μg/kg. Compared to the original QuEChERS method，the proposed method was rapid and accurate,and could significantly reduce matrix interference.