Cervical cancer has the second highest incidence of malignant tumors in women. There are about 500,000 new cases of cervical cancer worldwide each year, and about 233,000 women die from the disease, of which 80 new cases occur in developing countries. There are about 140,000 new cases of cervical cancer in China each year, and the number of new cases in China accounts for 1M3 of the incidence worldwide each year. In recent years, the incidence rate of cervical cancer has been increasing significantly and the trend is younger, and the incidence is growing at a rate of 2~3 per year. Since cervical cancer has a long reversible precancerous period, it takes about 10~15 years to develop from cervical precancerous lesion (CIN) to cervical cancer. Therefore, understanding early screening to detect cervical precancerous lesions is an important part of cervical cancer prevention and treatment. Cervical cancer is currently the only gynecological cancer that can be detected early and can be cured. I: At present, the common clinical examination methods are: cytological examination (Pap smear. Liquid-based cytology), human papillomavirus (HPV) test. Acetic acid staining for visual examination. Iodine staining for visual examination. Colposcopy. Cervical biopsy. Cervical canal scraping, etc. Option 1. A combination of HPV testing and liquid-based cytology (TCT) may be used. This option has more advanced screening techniques. It has a lower rate of leakage. It is the best screening option. Epidemiological studies have shown that high-risk HPV infection of the genital tract is a major risk factor for cervical cancer and cervical intraepithelial neoplasia (high incidence) in women, with 100% of cervical cancer patients positive for high-risk HPV infection, about 97% positive for high cervical intraepithelial neoplasia (CIN II and CIN III), and about 61.4% positive for low-grade lesions (CIN I). The relative risk of HPV infection compared to normal subjects was 254.2 and 26.4 for high intraepithelial cervical lesions and cervical cancer (≥CIN II) and low grade lesions (CIN I), respectively. Therefore, the 1995 IARC symposium concluded that HPV infection is the primary cause of cervical cancer . HPV is a group of DNA viruses with viral particles about 55 nm in diameter and a 20-sided symmetric core-shell with 72 capsids. Its genome length is about 8Kb and can be divided into three functional regions namely early go, late region and long regulatory region. Up to now, more than 200 HPV types have been identified, with different DNA endonuclease profiles and different shell protein antigenicity, but their viral morphology is similar and all have epitheliophilic properties. Low-risk HPV types such as HPV6, 11, 42, 43, 44, etc. often cause benign lesions such as external genital warts, including cervical intraepithelial lesions (CIN I). High-risk HPV types such as HPV 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, etc. are associated with the development of cervical cancer and cervical intraepithelial neoplasia, especially HPV 16 and 18. It takes about 20 years for a woman to develop cervical cancer after persistent infection with high-risk HPV types. In general, HPV infection is usually classified as latent infection, subclinical infection, clinical infection, clinical symptoms and HPV-associated neoplasia. Thinprep cytology technique (TCT): A special plastic cervical brush is used to collect cells from the ectocervix and the cervical canal separately, and the collected cells are washed into vials containing Thinprep cell preservation solution, which preserves almost the entire specimen obtained on the sampler and avoids the artifact of excessive cell drying caused by the conventional smear process. The specimens in the preserving solution were programmed by the Thinprep 2 000 system to make thin cell smears of 2 cm in diameter, fixed in 95% alcohol, and stained with Pap stain before being read by the physician under the microscope for diagnosis. The abnormal cells in the smear can be easily observed, and the nucleus structure of the wet-fixed cells is clear and easy to identify, reducing the false-negative rate. TCT has become the preferred method for cervicovaginal cytology in obstetrics and gynecology at home and abroad. Option 2 can use a combination of traditional Pap smear and rapid human papillomavirus (HPV) testing for colposcopic biopsy and pathologic histology in cases with abnormal cytologic results. Pap smear (PAP) method: As a screening method for cervical cancer, it is easy to perform and cost-effective. Its use has significantly reduced the morbidity and mortality rate of cervical cancer. However, it is affected by scraping, smearing and reading, and the false-negative rate is as high as 28%, which is difficult to provide sufficient basis for cervicovaginal cytology diagnosis and early treatment. Option 3 uses visual observation to perform screening by applying a certain concentration of acetic acid or iodine to the cervix to stain it for observation. These areas often do not have physicians for cytologic diagnosis and lack the equipment and technology for thin-layer liquid-based cytology and HPV testing. The method is to diagnose cervical lesions by applying a chemical solution to the surface of the cervix and directly observing the response of the cervical surface epithelium to staining with the naked eye of the physician under conditions of no magnification. The cervical epithelium becomes white when a 5% acetic acid solution is applied first, then a 5% compound iodine solution is applied and the iodine does not stain as suspicious. Visual examination is a relatively simple method that is less dependent on operational facilities, but the sensitivity and specificity are relatively low, ranging from about 50% to 70% and 85%, respectively. Most of the cases detected are not early lesions. Option 4: Colposcopy, a low magnification microscope with a magnification of 4 to 40 times, allows direct observation of the morphological structure of the vasculature and epithelium on the surface of the cervix. Colposcopy allows for more accurate targeting of the biopsy, differentiation of the nature of the lesion, and increased positivity of the biopsy through the observation of fine structures. Early screening and diagnosis are achieved. Colposcopy is a noninvasive test that allows dynamic observation of lesion development, close monitoring of disease changes, and long-term follow-up after treatment. Colposcopy is an effective tool for screening asymptomatic women for cervical lesions, with the main goal of screening for precancerous lesions and determining the extent of lesions. Experienced physicians will perform biopsies at the most obvious abnormalities on the cervical migratory zone to increase the specificity and sensitivity of the biopsy. Colposcopic visual indicators respond to the abnormality of the lesion with four main signs: border morphology, color, vascular structure and iodine response. The severity of abnormal colposcopic images is determined by several factors; increasing nuclear volume of cells within the abnormal epithelium leads to a whitish appearance of the septated epithelium after application of acetic acid; reduced glycogen in immature cells shows that this area remains uncolored after application of iodine solution; milder lesions are lightly flat and somewhat blurred with poorly defined lesions; severe lesions tend to be raised with clear borders; heterogeneous vasculature is a sign of a progressive lesion CIN I is often seen as flat white thickened epithelium with blurred borders and may have blurred mosaic; CIN II is seen as raised white epithelium with clear borders, and the transformation zone of squamocolumnar junction is visible; CIN III is a raised lesion with thickened dotted vessels and clear borders, with thick dotted vessels and mosaic, which is not colored after iodine application, and occasionally irregular composition of heterogeneous vessels is seen. Complex images of heterogeneous vessels, rock-like protrusions or lard-like changes are seen in infiltrating carcinomas. Colposcopy has a higher diagnostic compliance rate with histology compared to cytology, and colposcopy and cytology are two complementary screening diagnostic techniques, with colposcopy correcting false-negative cytologic findings. However, the interpretation of colposcopic images is somewhat subjective and can influence the diagnosis and choice of biopsy site. WHO recommends that women aged 25-65 years who have had sex should be screened for cervical cancer. It takes about 10 years for early precancerous lesions (CIN) to develop into invasive cancer, so if women can only be screened once in their lifetime, the best time is between the ages of 35 and 45. Screening is performed once a year for the general population and can be rescheduled to 3 years after 2 consecutive normal cytologies; 2 consecutive HPV tests and normal cytologies can be rescheduled to 5~8 years after. The combination of cytology and HPV testing as the primary screening method is more appropriate for a smaller number of women over 30 years of age who have transient HPV infection. 2: High-risk group: High-risk group refers to: (1) women with multiple sexual partners or frequent sexual intercourse; (2) women with low age of first sexual intercourse; (3) women whose male sexual partners have other cervical cancer sexual partners; (4) women with current or previous herpes simplex virus infection; (5) women with HIV infection; (6) women with other sexually transmitted diseases, especially a mixture of multiple sexually transmitted diseases ; (7) women who are receiving immunosuppressive therapy; (8) women who smoke; (9) women who have had cervical lesions, such as those with untreated chronic cervicitis, CIN and a history of genital tract malignancy. The use of HPVDNA testing can predict the risk of lesion deterioration or postoperative recurrence and effectively guide postoperative follow-up. In conclusion, cervical cancer starts from atypical hyperplasia of cervical epithelium and gradually progresses to invasive cancer through carcinoma in situ, and the development process takes 5~10 years or longer, so there is sufficient time for secondary prevention (i.e. early detection, early diagnosis and early treatment). Timely and effective detection and treatment of precancerous lesions can significantly reduce the occurrence of cervical cancer. At present, the technology of cervical cancer screening, early diagnosis and early treatment is very mature. Appropriate selection of cervical cancer screening methods can achieve twice the result with half the effort. Thus, the screening rate of cervical cancer and the detection rate of early lesions can be improved, and the death rate can be reduced. The survival rate can be improved.