In this study, a CoFe2O4/AuNPs/IL (ionic liquids) nanocomposite modified glassy carbon electrode (GCE) (CoFe2O4/AuNPs/IL/GCE) was developed as an electrochemical sensor for the sensitive detection of As(III) in soil using square wave anodic stripping voltammetry (SWASV). Taking advantages of the catalytic systems of AuNPs, Fe(II)/Fe(III), and Co(II)/Co(III), along with the excellent adsorption capability of CoFe2O4 and the good conductivity of the IL, the proposed sensor exhibited an enhanced detection performance toward As(III). Additionally, the relevant parameters affecting the stripping peak current of As(III) were optimized, resulting in a detection limit of 0.22 ppb (S/N = 3) and a sensitivity of 0.69 µA ppb-1. Furthermore, the interference of high concentrations of nontarget ions on the peak current of As(III) was evaluated, wherein the current change rate was less than 10 %. Moreover, the developed sensor exhibited good stability and reusability with a relative standard deviation (RSD) of 1.44 % after repeating the measurements five times. The probable mechanism of the enhanced stripping signal based on a dual electrocatalysis system was investigated by X-ray photoelectron spectroscopy (XPS). Finally, the proposed CoFe2O4/AuNPs/IL/GCE sensor was successfully applied to the detection of As(III) in real soil samples, which demonstrated its good practical utility for the accurate detection of As(III) in environmental monitoring.