Cervical cytology, colposcopy and histopathology, or the three-step technique, are the basic principles and standard treatment procedures for screening, diagnosis and management of cervical pre-cancerous lesions. The first step, cervical cytology examination usually adopts liquid-based thin-layer cytology (TCT) examination, which is a liquid-based thin-layer cell detection system to detect cervical cells and make cytologic classification and diagnosis, and it is a more advanced cervical cancer cytology examination technique internationally. Compared with traditional Pap smear, TCT significantly improves the detection rate of abnormal cervical cells, and the detection rate of cervical cancer cells by TCT cervical cancer cytology is 100%, and it can also detect some precancerous lesions. Colposcopy Colposcopy is the use of a colposcope to magnify the epithelium of the vaginal area of the cervix 10-40 times under strong light source to directly observe microscopic lesions that are invisible to the naked eye and to perform localized biopsy in suspicious areas to improve the diagnosis rate of cervical diseases. According to statistics, if biopsy can be taken with the assistance of colposcopy, the diagnostic accuracy of early cervical cancer can reach about 98%, but colposcopy cannot replace scraping cytology and biopsy, nor can it detect lesions in the cervical canal. The third step is pathological examination. Pathological examination is usually performed under colposcopy with biopsy forceps at the squamocolumnar junction of the ectocervix, and multi-point sampling can be performed at 3, 6, 9 or 12 points if cervical cancer is suspected. Pathological diagnosis is the final criterion to confirm the diagnosis of cervical cancer.