Ionic liquids modified CaFe2O4 magnetic nano-particles (MNPs) were synthesized, and a nano-hybrid of ILs-CaFe2O4 MNPs and MWCNTs are designed via a facile preparation method in order to fabricate a modified electrode. The modified electrode exhibits an obvious electrocatalytic activity toward the oxidation of bactericide carbendazim (CBZ). Based on the synergistic effect of ILs-CaFe2O4 MNPs and MWCNTs, the electrochemical trace-level detection of CBZ in paddy water and commercial fruits were realized. The impacts of experiment conditions on the electrochemical behavior of CBZ were studied. In addition, the sensor can be applied to quantification of CBZ in the concentration range of 3.14 x 10(-8) to 1.05 x 10(-5) mol L-1 and from 1.05 x 10(-5) to 1.05 x 10(-4) mol L-1 with a low detection limit of 9.41 x 10(-9) mol L-1 (S/N = 3). Moreover, ILs-CaFe2O4/MWCNTs electrode showed good stability, high selectivity, and satisfactory anti-interference ability. Satisfactory results indicated that ILs-CaFe2O4/MWCNTs nano-hybrid is a promising sensing platform for the trace-level analysis of bactericide residue CBZ in agricultural crops and environment. (C) 2016 The Electrochemical Society.