For frozen embryo transfer, the artificial cycle takes about 30 days-90 days, which needs to be judged on a case-by-case basis. Transfer of frozen embryos is usually done around the time of ovulation, and the thickness of the endothelium needs to be more than 0.7 centimeters. If there is ovarian insufficiency, it is necessary to establish an artificial cycle, i.e., exogenous supplementation of estrogen and progesterone to increase the thickness of the lining. Generally, estrogen is used on day 2-3 of menstruation, followed by ultrasound to detect endothelial changes, and progesterone is used to help with endothelial transformation around day 14, after which the endothelial transformation can be achieved in about 3-5 days, thus creating the conditions for performing frozen embryo transfer. However, some women are not yet able to achieve adequate endothelial preparation in one cycle, and require 2-3 manual cycles of conditioning, and therefore a longer period of time. Therefore, in embryo transfer, the recommended artificial cycle time for transferring frozen embryos is about 30-90 days, and the specific time needs to be judged in conjunction with the woman’s preoperative endothelial status. Generally, one cycle of medication can achieve a good state of readiness, i.e., the transfer can be carried out in 30 days or so, but a small number of women need 2-3 cycles of conditioning, and the time required may be extended to 90 days.