The whole procedure of colposcopy: 1. 3-7 days after menstruation. 2. no contraindications and normal leukorrhea routine after examination. 3. routine disinfection of the vulva and vagina, opening the vagina with a speculum and wiping the local mucus of the cervix before colposcopy. 4. first use the colposcope to magnify the cervix for observation, to understand whether there are local abnormal blood vessels and whether other abnormalities are used. apply acetic acid locally to understand whether there is acetate epithelium, especially the thicker clearly bounded acetate epithelium, which is basically the site of the lesion. After observing the acetic acid epithelium, iodine is applied locally, mainly to observe whether there is mustard yellow change, if there is mustard yellow, biopsy is taken from the mustard yellow area and sent for pathological examination, then local pressure gauze is applied to stop bleeding and colposcopy is completed.