The length of the cervical canal needs to be greater than 3 centimeters at 22 weeks of pregnancy in general. The cervical canal is a tube structure in the center of the uterine cervix, which is connected to the uterine cavity and the vagina. It is an important indicator for pregnancy checkups, and pregnant women can usually find out its length through vaginal ultrasound at 22 to 24 weeks of pregnancy. At 22 weeks of pregnancy, the length of the cervical canal should be greater than 3 cm. If it is less than 3 cm, especially less than 2.5 cm, cervical insufficiency should be considered, and the possibility of preterm labor exists. For ordinary women, the length of the cervical canal does not have much effect, but after pregnancy, the cervical canal is the channel for the delivery of the fetus, so its length has a certain impact on whether the fetus will be delivered prematurely, for the examination found abnormalities, it is recommended to bed rest in a timely manner, and if necessary, can be guided by the physician to carry out birth control treatment.