Luteinizing hormone is a gonadotropin, referred to as LH, is secreted by basophil cells in the anterior pituitary gland. It is a key hormone that stimulates the release of eggs and the formation of the corpus luteum, and can only initiate ovulation when its secretion is normal and reaches a certain amount. The average woman of childbearing age ovulates regularly once a month. Ovulation time (ovulation period) is usually 12 to 16 days before the next menstrual period. The eggs are usually only viable for 12 to 30 hours. Male sperm can survive for 2-3 days in the female reproductive tract, and the actual critical time for conception is only several hours. Therefore, the accurate prediction of ovulation period is of great significance for guiding the population preparing for pregnancy to seize the most fertile time and increase the chance of getting pregnant.