Genetic engineering is the core of modern bioengineering. Genetic engineering (or genetic engineering, gene recombination technology) is to cut and combine the genes of different organisms in vitro, connect them with the DNA of vectors (plasmids, phages, viruses), and then transfer them into microorganisms or cells for cloning, so that the transferred genes can be expressed in cells or microorganisms to produce the required proteins. More than 60% of biotechnology achievements are concentrated in the pharmaceutical industry to develop characteristic new drugs or improve traditional medicine, which has led to major changes in the pharmaceutical industry and the rapid development of biopharmaceuticals. Biopharmaceutical is the process of applying bioengineering technology to the field of drug manufacturing, the most important of which is genetic engineering. That is to cut, insert, connect and recombine DNA by using cloning technology and tissue culture technology, so as to obtain biomedical products. Biological drugs are biologically activated preparations prepared with microorganisms, parasites, animal toxins and biological tissues as starting materials, using biological processes or separation and purification technologies, and using biological and analytical technologies to control the quality of intermediate products and finished products, including vaccines, toxins, toxoids, serum, blood products, immune preparations, cytokines, antigens Monoclonal antibodies and genetic engineering products (DNA recombination products, in vitro diagnostic reagents), etc. Biological drugs that have been developed and entered the stage of clinical application can be divided into three categories according to their different uses: genetic engineering drugs, biological vaccines and biological diagnostic reagents. These products are playing an increasingly important role in diagnosing, preventing, controlling and even eradicating infectious diseases and protecting human health.