Egg freezing, known as egg freezing technology, is a medical technology that refers to the freezing and ultra-low-temperature storage of oocytes (generally stored in liquid nitrogen at -196℃) for the treatment of infertility and the preservation of women’s fertility, and it belongs to the derivation of assisted reproduction technology. At present, the main application scenarios of egg freezing technology in China are: 1. On the day of egg retrieval in IVF treatment cycle, when the male partner is unable to provide sperm in time due to various reasons, the female partner can save the oocytes taken out by emergency freezing, or save the remaining eggs taken out by this technology for backup, etc. 2. Cancer patients with fertility needs can utilize egg freezing technology for fertility preservation after evaluation prior to surgical radiotherapy treatment. In addition, it should be noted that egg freezing by single women for the purpose of delaying childbearing does not comply with the current laws and regulations of China.