There are three main types of contraceptives that are more common in clinical practice, namely short-acting oral contraceptives, long-acting contraceptives and emergency contraceptives. The contraceptive mechanism of different contraceptives is basically similar, but there is a certain degree of difference. 1, the main role of short-acting oral contraceptives, through the body’s hormone regulation to achieve the inhibition of ovarian ovulation. That is, during the use of short-acting oral contraceptives, women generally do not normally ovulate, so as to play a contraceptive effect. 2, long-acting contraceptives mainly rely on the improvement of the body’s hormone levels, to play a suppression of ovulation, while regulating the body of the thickness of the endometrial lining. Compared to short-acting oral contraceptives, its hormone concentration is obviously high, so the side effects are relatively large. 3, emergency contraceptive pills in a short period of time after the use of the drug can quickly regulate the body’s hormone levels, play a role in inhibiting the combination of sperm and egg, and also inhibit the fertilization of the egg.