Recently, I have read a lot of patients about cervical lesions, and many of them are about the diagnosis and treatment of cervical intraepithelial neoplasia (CIN). For this common problem that plagues women’s health, I would like to make a brief introduction here, hoping that my explanation can make women who are plagued by this disease get relief and go to the regular treatment received by the regular hospital and take as few detours as possible. The diagnostic principle of CIN requires a three-step diagnostic technique. 1, first cervical screening, cytology is preferred (combined application of cytology and HPV-DNA testing is recommended for women over 30 years of age); 2, colposcopy for those with abnormal screening; 3, colposcopic cervical biopsy or cervical scratching for pathological examination if necessary, pathological histological findings are the gold standard for the diagnosis of CIN. From the above explanation, cytology and colposcopy results cannot be used as the final diagnostic criteria for the disease, and histological results must be available for the next step of treatment. If the result of cervical screening cytology is: atypical squamous cells without clear significance, the treatment advice is: repeat cytology or direct colposcopy after 6 and 12 months, and if there are symptoms (contact bleeding or bloody leucorrhea, etc.) a cervical biopsy is feasible to clarify the diagnosis. If the result is: atypical glandular cells without clear significance, cervical duct scratching is recommended for a definitive diagnosis. CIN is divided into CIN I, CIN II and CIN III, which are treated differently depending on the extent of the disease. Most of the CINⅠ can subside naturally without treatment, and physical therapy such as laser, electrocautery, freezing and microwave can be used for those who have symptoms. If CIN Ⅰ recurs after treatment, electrocycloplasty (LEEP), laser conization or cold knife conization can be used. Total hysterectomy is not the treatment of choice for CIN II/III. After cervical conization to exclude invasive cancer, total hysterectomy can be considered in the following cases: those who do not have fertility requirements and insist on hysterectomy; those whose conization margins are still highly diseased and cannot be easily reexcised for localized cervical lesions; those with recurrent or persistent CIN II/III; and those who do not have the conditions for follow-up. Follow-up is mandatory after CIN treatment. The first review will be done 4-6 weeks after treatment, every 6 months for 2 years and annually after 2 years. Routine screening after 4 normal retests.