To establish a rapid and sensitive method for detecting trace amounts of benzo[a]pyrene (BaP) in food, an AB@Co3O4@MWCNTs-COOH nano-electrochemical sensor was developed using Acetylene Black (AB), magnetic cobalt oxide (Co3O4) nanoparticles, and carboxylated carbon nanotubes (MWCNTs-COOH). The composite material AB@Co3O4@MWCNTs-COOH was used to modify the electrode surface. The electrochemical reaction of BaP on various sensors was investigated using cyclic voltammetry (CV). A distinct oxidation peak with no corresponding reduction peak was observed, indicating an irreversible oxidation-reduction process. The AB@ Co3O4@MWCNTs-COOH sensor was characterized by scanning electron microscopy (SEM), CV, and electrochemical impedance spectroscopy (EIS), and the operating conditions were systemically optimized. The optimal conditions were as follows: electrolyte solution of lithium perchlorate (0.3 mol/L, pH 2); a modification solution volume ratio of VCo3O4@MWCNTs-COOH to VAB was 2:1, a total modification volume of 6 μL, and an enrichment time of 15 min. Under these conditions, the oxidation peak current of BaP showed a strong linear correlation with concentration, with the regression equation Ip = 3.1939CBaP+1.5439 (R2=0.996). The limit of detection (LOD) was 3.12×10-10 mol/L. Application of this method to barbecued meat samples yielded recovery rates ranging from 84.34% to 93.36%. The proposed sensor demonstrates ease of operation, ultra-low LOD, strong anti-interference ability, and high stability, making it suitable for rapid on-site screening and quantitative analysis of BaP in food.