CIN (cervical intraepithelial neoplasia) is a precancerous lesion that may be normal in appearance but has abnormal proliferative cytologic or tissue changes, and is intermediate between a “pathologist’s disease and a patient’s disease”, having both epithelial cell heterogeneity and maintaining some differentiation. In a sense, it has the potential to develop in both directions. Depending on the extent of the lesion, CIN can be divided into CINI, CINII and CINIII, and it is difficult to predict the outcome of each case of CIN, all of which have a risk of further malignant progression, with CINI, CINII and CINIII having a 15%, 30% and 45% risk of developing cancer, respectively, and even CINI or CINII can develop directly into invasive cancer without going through CINIII. even CINI or CINII can develop directly into invasive carcinoma without going through the CINIII (including cervical carcinoma in situ, CIS) stage. Although there are some lucky individuals who regress or reverse spontaneously without treatment, this is difficult to assess in each case, so it is not advisable to take a chance. In any case, the fact that CIN is 20 times more likely to develop into carcinoma in situ and 7 times more likely to develop into invasive carcinoma is a reason to take CIN seriously and treat it properly! In the continuum of CIN-early invasive carcinoma-infiltrating carcinoma, the correct treatment can interrupt this process. For 90% of women, the natural evolution from cervical lesion to cancer usually takes about 5-10 years, which is an important and non-negligible period of time. Cervical cancer is a preventable and curable disease, and the key lies in the timely diagnosis and treatment during this period. The combination of liquid-based thin-layer cytology and HPV testing can detect 99% of high grade lesions and 83.5% of low grade lesions. Modern detection technology makes cervical cancer the only tumor that can be fully controlled through efforts, which is why the state has included cervical cancer and breast cancer in the “two cancers” control for women.