Abstract: Three-dimensional porous structured graphene by one-step irradiation of polyimide film with high-energy beams was prepared, and the high-precision assembly of patterned flexible electrode (LIGE) array was realized simultaneously. The nitrogen-doped carbon supported Mg single-atom catalyst (MgNC) was modified on the working electrode to construct MgNC/LIGE sensing platform with high surface area and excellent catalytic property. The electrochemical sensing analysis of fungicide carbendazim was performed using cyclic voltammetry and differential pulse voltammetry, and the results showed that the current response of carbendazim was sensitive on MgNC/LIGE. The oxidation peak current of carbendazim was linearly increased with its concentration in the range of 1.0 nmol/L~55 μmol/L (R=0.999) with a limit of detection of 0.23 nmol/L (R_SN=3). The carbendazim in environmental and food samples was detected based on standard addition method with a recovery of 97.2%~102.0%, indicating the reliability of the MgNC/LIGE for carbendazim detection in complicated samples. This sensing platform has the advantages of simple manufacturing process, environmental friendliness and low cost, which has good application prospect.