A modified screen-printed carbon electrode was prepared and manufactured by using ionic liquid, nano-Fe 3O 4 and in situ plating bismuth film methods, which were used to detect heavy metal ions of cadmium and lead by stripping square wave voltammetry. Some electrochemical methods such as cyclic voltammetry, electrochemical impedance spectroscopy and square wave stripping voltammetry were further applied to investigate the properties of this electrode. It illustrated that the formed bismuth film/ionic liquid/nano-Fe 3O 4 layer on the top of screen-printed carbon electrode could remarkably improve the electron transfer and the specific surface area of the electrode owing to ionic conductivity and adhesiveness of IL and high electron transfer of nano-Fe 3O 4. Under the optimum conditions, the linear detection range of modified electrode was 0.2 ~ 35.0 μg/L and 0.2 ~ 20.0 μg/L for cadimium and lead with detection limit of 0.06 μg/L and 0.1 μg/L ( S/N =3). Finally, the proposed analytical procedure was applied to detect trace metal ions in real samples with satisfactory selectivity and results.