Drug abortion mainly uses mifepristone and misoprostol. The principle of these two drugs in doing abortion mainly has the following contents. First, mifepristone is mainly a progestin antagonist, which can antagonize progesterone and make progesterone lose its effect. The development of female embryos must be supported by progesterone, so in the absence of progesterone, the embryo will gradually lose its activity and die. After the embryo dies, the embryonic tissue and meconium will gradually separate from the uterine wall, so the patient may experience vaginal bleeding and abdominal pain. Secondly, misoprostol, the main function of misoprostol is to promote uterine contraction and also to soften the cervix. Therefore, when the uterus is contracted, the pressure of the contracting uterus is used to promote the expulsion of the embryo and meconium. When the patient’s cervix is softened, the embryo and meconium will be expelled more smoothly. Since the cervix is normally closed, when the cervix is relaxed, it is easier for the patient’s cervix to open and facilitate the expulsion of the tissue from the uterine cavity, so that the purpose of medical abortion can be achieved.