Objective : To establish a microwave-assisted digestion-inductively coupled plasma mass spectrometry (ICP-MS) with an octopole reaction system for simultaneous determination of six heavy metals in peanuts, including Cr, Ni, As, Cd, Pb, Hg. Methods : Peanut samples were shelled and crushed evenly, and 0.350 0 g was accurately weighed and digested with 5 mL nitric acid and 1 mL hydrogen peroxide in a digestion tank. Following microwave-assisted digestion, pure water was used to quantify the samples, and internal standards and an octopole reaction system were used to remove the interference. Then, the contents of six heavy metals were determined in peanuts by ICP-MS. The accuracy and precision of ICP-MS were evaluated using national criteria ( GBW 10013 and GBW 10044 ) and spike-and-recovery testing. Results : The six heavy metals showed good linearity at the selected linear range ( r≥0.999 8 ). The detection limits of ICP-MS ranged from 0.001 4 to 0.023 8 ng/mL, and the spike-and-recovery rates ranged from 94.7% to 98.8%, with the relative standard deviations ranging from 0.7% to 3.6%. In addition, the determination results of the standard reference materials were all within the normal reference range. The detection of six heavy metals was 100.0% in 60 peanut samples, and the contents of six heavy metals were all low. Conclusion The established ICP-MS assay is feasible for simultaneous determination of multiple heavy metals in peanuts.