SnO2/SiC hollow spheres, polyaniline nanowires, gold nanoparticles and other nano materials with good biocompatibility were modified on the electrode substrate and antibody probe to amplify the electrochemical signal, improve the detection sensitivity, and construct a direct competitive detection electrochemical sensor for aflatoxin B1. The results showed that the detection linear range of the sensor for aflatoxin B1 was 3.81 pg/mL~1.00 μg/mL, and the limit of detection was 1.13 pg/mL. The proposed sensor had good stability, reproducibility and specificity, and the detection recovery of the edible oils was between 84.6% to 107.6%, with the coefficient of variation between 5.42% to 10.49%, indicating that it can be used for the rapid screening of aflatoxin B1 in edible oils.