Cervical smear, also known as cervical smear, is an important method of cervical cancer screening. The cervical smear is usually taken at the squamous epithelial junction of the ectocervix, which is the preferred site for cervical cancer, and a small scraper is used to gently scrape a week with the ectocervix as the center of the circle. The cytological examination of cervical scraping is used for the diagnosis of gynecological tumors, mainly the Pap classification, which has five levels of diagnostic criteria. Generally, Pap grade IV is highly suspicious cancer, Pap grade III is suspicious cancer, and Pap grade V is cervical cancer with a typical amount of multiple cancer cells. For Pap grade III or above, cervical biopsy is recommended to clarify whether there is cervical lesion. Cervical smear is used for gynecological tumor diagnosis, which is only a screening method and cannot confirm the diagnosis. Currently, Pap smear has been gradually replaced by TBS classification method, and the sampling method used for TBS classification is what is now called cervical liquid-based cytology examination.