LEEP knife treatment for CIN is currently a common clinical procedure with good clinical results, which can effectively remove the diseased tissue and prevent the occurrence of cervical cancer. Its advantages include less trauma, less intraoperative bleeding, less postoperative infection, less pain, faster recovery, and less disruption of normal life and work; most importantly, LEEP knife treatment for CIN can fully satisfy the patient’s desire to preserve the cervix and fertility, and is an effective and safe surgical treatment for women of childbearing age with CIN. However, the study showed that the difference in the incidence of vaginal delivery and cesarean section between the control and study groups was not statistically significant, indicating that LEEP surgery is not only effective but also safe in the long term. In terms of pregnancy outcome, there was no statistically significant difference in the incidence of premature rupture of membranes, production of cervical laceration, postpartum hemorrhage, low neonatal body mass and neonatal asphyxia between the two groups of subjects, but the preterm delivery rate in the post-LEEP surgery group was significantly higher in the study group than in the control group, and the difference was statistically significant. It is suggested that the maternal and infant outcomes of pregnancies in women after LEEP knife treatment for CIN are basically similar and safe, but there are still high-risk factors for preterm delivery in women after LEEP surgery, and the causes of the effects should be actively explored, and careful clinical observation should be implemented for this group of mothers to reduce the incidence of preterm delivery. The factors that may cause preterm labor after LEEP knife treatment of CIN are considered to be: 1. CIN itself is an inflammatory infiltrative disease, and as the disease progresses, it may cause changes in the immune circulatory system in the patient’s cervix, destroying cytokines in early pregnancy and reducing anti-infection ability, resulting in post-pregnancy infection and other problems, which may easily cause preterm labor; 2. LEEP surgery is invasive surgery, and if the postoperative treatment is improper or patients’ lack of self-care awareness, infection may also occur and cause preterm labor; 3. The removal of cervical tissue may cause cervical insufficiency in some patients and trigger preterm labor. It is shown that there is no significant effect on the mode of delivery after LEEP knife treatment for CIN, and it has little effect on pregnancy outcome, but it may increase the incidence of preterm delivery, so the management of pregnant women with a history of CIN via LEEP surgery should be strengthened.