Cervical intraepithelial neoplasia (CIN) is a pre-cancerous lesion of the cervix caused by human papillomavirus (HPV) infection, which is pathologically classified into three grades: CIN grade I, CIN grade II and CIN grade III. CIN grade III is also known as carcinoma in situ. After the human body is infected with HPV virus, if the immune system is strong, it can clear the HPV virus in the body and make CIN reverse transformation or even return to normal cervix; however, if the HPV virus keeps replicating in the body, it may develop into invasive cervical cancer. Patients with CIN may have symptoms of increased vaginal discharge or contact bleeding and go to the hospital for cervical biopsy, while some patients have no obvious symptoms and are found during gynecological screening. Patients with CIN grade I need regular follow-up cervical smears or cervical liquid-based cytology; CIN grades II and III require surgical treatment, usually cervical LEEP or cervical conization with complete excision of the epithelium of the ectocervix and its underlying mesenchyme and serial pathology to assess the nature of the cervical lesion in order to avoid missing early microinfiltrating cervical cancer. The procedure is best performed after menstruation to avoid the onset of menstruation in the days following the procedure to affect the healing of the cervical wound and increase postoperative bleeding. Cervical biopsy can only reflect the local condition of the cervix, and the pathology report of cervical biopsy is not the same as the pathology report after cervical LEEP or cervical conization. If the pathology diagnosis after LEEP or cervical conization is CIIN grade II or CIN grade III, and there are no tumor cells left in the surgical margin, then the surgery achieves the ideal diagnosis and treatment purpose. If the postoperative pathology suggests invasive cervical cancer, further radical cervical cancer surgery of different extent is required depending on the depth of infiltration.