Many pathologies can occur in the cervical area, such as developmental malformations, inflammation, tumors, injuries, and even dysfunction. Cervical lesions plague many women and greatly affect their working life. At present, there are various methods to treat cervical lesions, among which cervical loop electrosurgery, also known as ultra-high frequency electrophoresis, commonly known as “LEEP knife”, is a more effective treatment. It is important for patients to know and understand the application of this technology in cervical lesions. Loop electrosurgical excision procedure (LEEP) was first reported by French scholar Cartier in 1981 and has been widely used in clinical practice since the 1990s. The principle is to generate 3.8 megahertz high-frequency electric waves through the electrode tip, and after contacting the tissue, the tissue itself absorbs the high-frequency electric waves and generates high heat instantaneously to finish the treatment of the cervical lesion. This technique is widely used in Europe and America for the diagnosis and treatment of cervical intraepithelial neoplasia (CIN). In recent years, domestic hospitals have also gradually popularized it in the treatment of cervical lesions. The advantages of LEEP】 UHF electric wave knife is composed of a variety of electrodes, including ring-shaped, spherical, needle-shaped, triangular (conical), square, etc. ① including all the functions of radiofrequency technology: cutting, coagulation, ablation, evaporation, removal, contraction, electrocautery (including all the functions of laser and electric knife, and without their side effects); ② precise surgery, can achieve very fine surgical results that can not be achieved by traditional electric knife; ③ minimally invasive: no pressure cutting, small tissue damage (damage depth is less than 20 microns, few fibers are formed, scarring rarely occurs after surgery) ; ④ less occurrence of tissue pulling and carbonization caused by traditional electric knife. ⑤ Less pain, less complications (less bleeding and infection); avoiding open surgery, reducing patient pain, less tissue damage, most of the cervix regains smoothness about 8 weeks after surgery, and maximizing preservation of uterine function. (6) Only the cancerous area is removed, preserving the uterus for women of childbearing age and maximizing the preservation of reproductive function. (7) Economical, safe, convenient, less complications, most patients do not need hospitalization, LEEP can be performed in outpatient clinic, short operation time (3~5 minutes) less bleeding, only need to operate 3~7 days after menstrual cleansing, high cure rate. Indications for LEEP】 (1) CIN confirmed by cervical cytology or biopsy and colposcopy can be treated by LEEP. (2) Classical indications for LEEP ① in cytology and colposcopy, those with suspected grade II or III cervical intraepithelial lesions (CIN Ⅱ to Ⅲ); ② persistent CIN grade I or CIN with inconvenient follow-up; ③ suspected cervical carcinoma in situ and early invasive carcinoma; ④ suspected atypical squamous cells of unknown significance (ASC-US) in the cervix; ⑤ symptomatic cervical ectopia. (3) Some scholars believe that LEEP can be used to remove highly squamous intraepithelial lesions (HSIL) of the cervix with lesions >2.5 cm that have been poorly treated by electrodesiccation and cryotherapy. Contraindications to LEEP】 ① acute pelvic inflammatory disease; ② trichomoniasis, vulvovaginal pseudomonal yeast disease, atopic vaginitis; ③ severe heart disease, liver disease, tuberculosis, hematological disease; ④ immunodeficiency disease; ⑤ adenocarcinoma of the cervix or adenocarcinoma in situ of the cervix. There are different opinions on whether the LEEP margin is charred or not and whether it will affect the evaluation of the specimen. Some pathologists do not report the cut edge or report significant burn on the cut edge. It is generally believed that LEEP can provide an intact specimen without charring and does not affect pathological examination. Sharon from abroad reported that thermal injury has a greater impact on the glandular epithelium, and for suspected invasive carcinoma or adenocarcinoma in situ, thermal injury by LEEP may affect the assessment of the depth of infiltration, therefore, it is considered inappropriate to use LEEP in these cases, and cold knife conization (CKC) is appropriate. If the lesion persists after LEEP (+), it is related to recurrence; however, the margin (-) does not absolutely guarantee no recurrence. Therefore, all postoperative follow-ups should be performed. If the margin (-) and cervical canal scraping ECC (-), cervical cytology will be performed 6 months after surgery until 3 consecutive negative results; if the margin (+) ECC (-), cytology will be performed once every 3 months for 2 times after surgery, and then once every 6 months for a total of 3 years. [Controversial issues in the application of LEEP] ① Indications: In the treatment of chronic cervicitis, LEEP knife is generally not advocated as the first choice. In chronic cervicitis, LEEP is only indicated for the combination of old cervical laceration, giant nuchal cyst, cervical canal proliferation, cervical canal laceration, cervical canal polyp formation, and failure of previous microwave or laser treatment for the purpose of local cervical reshaping. At the same time, the high cost and damage of LEEP surgery (compared to focused ultrasound) limit its use in the treatment of non-neoplastic cervical lesions. Therefore, we must strictly control the indications for the application of this technology in the treatment of chronic cervicitis to avoid overtreatment that would cause damage and burden to the patient. In addition, LEEP is not suitable for those with HPV and ASCUS only. It should not be used casually as a treatment for cervicitis and cervical erosion, and the indications should not be exaggerated. The “see-and-treat” protocol is also used for the treatment of cervical CIN, i.e. patients are diagnosed cytologically and are treated directly with LEEP without colposcopic biopsy or waiting for biopsy pathology results. The “see-and-treat” protocol is used for patients with HSIL cytology results to improve patient satisfaction and compliance and to reduce costs; the “see-and-treat” protocol is used for those with abnormal cytology and colposcopy, only for experienced colposcopists who can distinguish between HSIL and LSIL under colposcopy. The “see-and-treat” regimen is only indicated for those who can distinguish between HSIL and LSIL on colposcopy by experienced colposcopists, and for those with a clear diagnosis of HSIL on both cytology and colposcopy. ②Effects on future reproductive function: LEEP has certain effects on reproductive function and outcome, such as postoperative cervical stenosis, which becomes a barrier to sperm passage; cervical mucus loss and mucus reduction, which hinders the passage of sperm into the uterine cavity; cervical insufficiency, such as the large size of the excised cervix, which affects the structure of the cervix, may lead to midterm abortion, increased preterm delivery, and high incidence of premature rupture of fetal membranes. There are controversies about whether to do LEEP during pregnancy. Some believe that LEEP is safe in the first three months of pregnancy, while others believe that it is appropriate in the last three months of pregnancy. In addition, it was also found that those who did LEEP during pregnancy had residual lesions at the 3-month postpartum follow-up, while the original LEEP resection specimens were normal, so there is disagreement about whether LEEP can be done during pregnancy. In situ adenocarcinoma is not easily detected by cytology and colposcopy. When clinicians suspect adenovascular lesions, they often consider the patient’s age, the location of the lesion (ectocervix, endocervix or both), the possible hiding place of the lesion, the margin after conization, the desire to have children in the future and the compliance with the examination before making the choice of treatment. If in situ adenocarcinoma is unexpectedly found in the LEEP specimen and the ECC is also negative, for those who want conservative treatment or who want to preserve their fertility, they can be followed up with cytology, colposcopy and ECC without further LEEP, CKC or hysterectomy, usually every 4 months and then every 6 months.