The invention belongs to an immunodetection field and specifically relates to an optimized co-immunoprecipitation technology. Based on an original co-immunoprecipitation technology, the co-immunoprecipitation technology is combined with a protein crosslink technology. That is to say, a protein crosslinking agent is used to crosslink an antigen antibody complex; elution is carried out by the use of a specific buffer; and the immunoblotting detection remarkably reduces the pollution of heavy chain and light chain of the antibody in the experiment. According to the invention, specificity of the co-immunoprecipitation method is raised, the method is characterized by stability and repeatability, experiment efficiency is improved, and the method provides beneficial assistance for in-depth research in molecular biology, molecular oncology, cell biology, biochemistry and the like.