Abstract:Pig production is an important component of animal husbandry industry in China. Domestic pig production mainly uses self-breeding mode. The semen used in pig reproduction mostly uses fresh semen or diluted semen stored in room temperature, and semen cryopreservation technology can make the long-term preservation of pig semen. Compared with cattle, mice and other species, the cryopreservation technology of pig semen needs to be further optimized and improved. This review summarizes the development of frozen pig semen, the main technical process, the key factors affecting sperm motility after freezing and thawing, including semen collection, pre-cooling balance before freezing, addition of cryoprotectant agents, and cryopreservation methods. It also covers the physicochemical changes during the sperm cryopreservation process, such as physical structural damage, functional damage, and sperm anti-freezing mechanisms. Finally, new methods to improve the cryopreservation efficiency of pig sperm are summarized, including nanotechnology treatment of semen and the study of cryopreservation biomarkers for sperm,in order to provide theoretical reference for perfecting porcine frozen semen technology and accelerating its application in pig production.