In this study, we presented a simple, rapid and sensitive colorimetric assay for the detection of cadmium (Cd) based on enzyme-linked oligonucleotides. The specific binding of aptamer to Cd²⁺ led to the decrease of horseradish peroxidase(HRP) on the microtiter plate, since HRP could not be bind onto through the hybridization of the aptamer and complementary DNA strand. It resulted in the change of characteristic peaks at 450 nm, helping to quantitatively detect Cd²⁺. Under the optimal conditions, the detection limit could be as low as 0.05 ng/mL, and the linear response for Cd²⁺ in a concentration range from 0.1 to 5 ng/mL(S/N=3). This method was simple and rapid, resulting in high sensitivity and specificity, and could be used in food safety analysis and environment monitoring.