A novel antigen-antibody reaction sensitizer is disclosed, which comprises HEPES buffer solution, bovine serum albumin BSA, sodium chloride solution and sensitizer, and the specific configuration of the reagent is as follows: the concentration of 1g/L of bovine serum albumin BSA, the concentration of 10g/L sodium chloride solution and the concentration of 0.5g/L of the sensitizer are mixed and stirred, and the concentration of 50mm HEPES buffer is added to adjust the pH of the reagent to 7.0. The present invention compares the test reagent 5 with the four test reagents, so that the generated aggregate reaction signal is amplified by hundreds of times, which is easy to detect by naked eye or instrument, and the sensitizer disclosed in the present invention has high sensitization performance, will not increase the viscosity of the reaction system, the repeatability and accuracy are better, and the sensitizer is safe during the test, so as to achieve the purpose of the present invention.