This study developed a method to assess the levels of three phosphorothioate pesticides (chlorpyrifos, tolclofos-methyl,quinalphos) in yacon that based on using a molecularly imprinted reversed matrix solid-phase dispersion (MI-MSPD) and accelerated solvent extraction (ASE) combined with GC-MS. The MIPs are cross-linked polymers with specific binding sites for a particular analyte, which recognize target molecules by imprinting a molecule during polymer synthesis through covalent or non-covalent interactions. The obtained MIPs was used to extract and preconcentrate three phosphorothioate pesticides as adsorbent of matrix solid phase dispersion from yacon sample in extraction pot and cell of ASE, then the samples were detected by gas chromatography-mass spectrograph(GC-MS)，and the positive ion mode of selected ion monitoring (SIM) with electron impact ionization source was adopted in MS. The results of 3 kinds of phosphorothioate agrochemicals identified in yacon samples in Wuhan area were satisfactory. The linear correlation was 0.9987-0.9996 between concentrations range of 0.01-2.5 μg/mL; the detection limit of the method was 0.174-0.526 μg/kg in yacon samples，the relative standard deviations were in the range of 2.3%-9.9% in yacon samples，the recoveries were in the range of 79.8%-104.5% in yacon samples.