The invention belongs to fields of immunochemistry analysis. It discloses an enzyme-uniting immune method and reagent box used in detection of quinoxaline-2-carboxyl acid residues, the method mainly contain medicine reconstruction, the preparation of immunogen, peridium antigen and antibody and pretreatment of sample and building of ELISA detecting method. The reagent box comprises quinoxaline-2-carboxyl acid (QCA) specificity antibody, QCA standard substance, enzyme target-object peridiumed with coupling substance of egg albumin and reaction production of QCA and gamma-aminobutyric acid. The sample is hydrolysed by metaphosphoric acid to discharge QCA, and cleaned by MAX column, derivatized by butyl amine, indirect competition ELISA is adopted in detection. The method and reagent box in the invention has advantages of simpleness, speediness, sensitivity and accuracy, large-lot samples can be detected fast and simultaneously, lowest detecting limit is 0.6 mug/kg.