Steps of cervical dilatation: I. Routinely disinfect the vulva and vagina. Second, place a vaginal speculum, expose the cervix, disinfect the vagina, cervix and cervical canal, clamp the anterior lip of the cervix and pull it outward, correct the uterine flexion position to a horizontal position, use a probe to carefully probe the direction and depth of the cervical canal, after the probe passes through the endocervical os, take out the probe, and then change to the cervical dilator to dilate the cervical canal. Third, the operator holds the dilator in a pen-like grip, and gently sends the dilator into the cervix to the endocervical orifice of the uterine cervix of 1cm-2cm. The starting size of the dilator is decided according to the patient’s degree of cervical tolerance, and it is generally started from No. 2-4, and gradually dilates up to No. 7-8; in case of tight cervix with poor elasticity, the dilator can be prolonged for longer period of time, and the dilator should not be used in a hasty manner so as to avoid cervical laceration. After the operation, take out the dilator, sterilize the cervix and take out the speculum.