Abstract: AP was coupled with BSA by glutaraldehyde method to prepare complete （coated） antigen AP-BSA. It was identified that the coupling was successful by ultraviolet scanning and the results of determination by ultraviolet absorption spectrophotometry showed that the coupling rate was 5：1. Through phalanx titration test, it was confirmed that the best coating concentration was 4 ~g/mL, the optimum working concentration of the first antibody was 1：3 000 and the optimum working concentration of the second antibody was 1：400. It was confirmed by two-factor repeated test that the optional coating conditions were as follows ： using CBS as coating buffer and overnight below 4 ℃.