Second generation IVF refers to the technique of intracytoplasmic single sperm microinjection of oocytes for fertilization. The second generation of IVF is suitable for men with severe oligozoospermia, weak and abnormal spermatozoa, irreversible obstructive azoospermia, such as congenital absence of the vas deferens, vas deferens blockage due to infection, etc. In addition, when the first generation of IVF has failed to fertilize repeatedly and the fertilization rate is very low, etc., the second generation of IVF can be used as well. The second generation of IVF is a micro fertilization technique developed on the basis of in vitro fertilization embryo transfer of the first generation of IVF, which directly injects sperm into the cytoplasm of the oocyte to complete fertilization, and the process after fertilization is actually the same as that of the first generation of IVF. It was developed mainly to solve male infertility.