A cervical canal of 22 mm is a relatively short state and carries the risk of preterm labor. However, it is not possible to specify how long it takes to enter labor and the pregnant woman should be treated accordingly according to the specific gestational week. The normal length of the cervical canal is 2.5-3cm and will gradually become shorter as the gestational months increase. If the cervical canal is <2.2 cm, especially for pregnant women with recurrent late miscarriages, cervical canal ligation is recommended at around 14-18 weeks of pregnancy. In addition, if the length of the cervical canal is <2.5 cm, it often indicates a risk of recent preterm labor and a higher chance of preterm labor, often associated with habitual miscarriage in the older months. Therefore, if the cervical canal shortens in late pregnancy, the first thing to do is to pay attention to more bed rest and fetal preservation, as well as to pay attention to uterine contractions. Once frequent contractions and abdominal pain occur, hospitalization is required. Pregnant women should take more rest, increase nutrition appropriately, maintain a certain amount of activity every day, and pay attention to regular maternity check-ups according to schedule.