Abstract: A novel glucose oxidase electrochemical biosensor was prepared by co-modifying glucose oxidase liposomes and nanographene on the surface of a glassy carbon electrode through self-assembly technology, and using it to construct a heavy metal residue detection system. The results showed that the ultrasonically processed graphene sheets were thinner and had a thickness of about 5 nm. Hg²⁺ and Cu²⁺ were used as models respectively. Hg²⁺ and Cu²⁺ showed oxidation peak currents at 0.15 and 0.20 V, respectively, and the peak current does not shift at different concentrations. In a certain linear range, the inhibition rate had a good linear relationship with ion concentration: Hg²⁺ was in the range of 10^-10~10^-5 and 10^-5~10^-2 mmol/L, the equations were I%=(0.0244 lgC+0.3543)% and I%=(0.1552 lgC+1.0219)%, the coefficient of determination R² value were 0.9747 and 0.9937, and the detection limits were 10.97 ng/mL and 3.60 ng/mL, respectively;the fitting equation for Cu²⁺ at 10^-10~10^-2 mmol/L was I%=(0.0406 lgC+0.8582)%, the coefficient of determination R² value was 0.9885 and the detection limit was 87.70 ng/mL, which indicated that the detection method had high sensitivity. The recovery test results shows that the established detection method has high accuracy and high precision for the detection of heavy metals, and has a good application prospect.