In principle, the incomplete clearance of medication abortion should not exceed 14 days, and the time of clearance will be determined by the amount of residues in the uterine cavity and the level of human chorionic gonadotropin in the blood of the patient. The abortion may not always be successful, and residues in the uterine cavity may occur. Therefore, it is important to review the ultrasound after the abortion to determine if there are residues in the uterine cavity. Usually, if the medication abortion is incomplete and the uterus is not cleared for a long time, it will affect the recovery of the uterus and lead to retrograde bacterial infection, which will eventually cause infection of the whole reproductive system, so in principle, it should not exceed 2 weeks. When there is less residue in the uterine cavity and no blood flow from the residue is found after ultrasound examination, the patient can use drugs to promote the discharge of the residue under the guidance of obstetrician and the operation of clearing the uterus can be not performed when the uterine cavity is found to be clean after reviewing ultrasound. In addition, it is important to pay attention to the amount of vaginal bleeding and the color change after the medication abortion, and to review the ultrasound 7-10 days after the medication abortion.