Cervical intraepithelial neoplasia, or CIN, is a group of precancerous lesions closely related to invasive carcinoma of the cervix, including cervical atypical hyperplasia and cervical carcinoma in situ, reflecting the process of successive changes occurring in the cervical cancer i.e., by the cervical atypical hyperplasia, known as CIN1 mild, moderate, and severe, and then occurring in the carcinoma in situ, the carcinoma in situ and then develop into a more serious series of changes of early invasive and invasive carcinomas. the CIN2 stage is equal to the Moderate atypical hyperplasia with cellular changes, mainly in the epithelial, subepithelial 1/2 or 1/3 of the site, will show abnormal nuclear hyperplasia, which will be more pronounced than when CIN stage 1. Obvious nuclear schizophrenia can be seen in the subepithelial 1/2, so CIN2 can directly develop into invasive carcinoma, but CIN2 is still moderate epitheliomatous metaplasia, and has not yet developed to the degree of carcinoma in situ. Therefore, in clinical practice, we must pay attention to patients with CIN2 grade, and must control it to prevent it from continuing to develop backward into cervical carcinoma in situ.