The diagnosis and treatment of gynecological diseases requires a vaginal examination in many cases. Women have cyclical menstrual cycles and the timing of the examination should be chosen according to the timing of the menstrual cycle. If the timing of the consultation is appropriate, it will not only facilitate the diagnosis of the disease, but also the treatment. Generally, gynecological examination is not carried out during menstruation because the uterine opening is slightly open during menstruation, and the endometrium has traumas, so it is very easy for bacteria to be brought in during the examination and cause inflammation of the endometrium, fallopian tubes and other reproductive organs, and if not properly dealt with, it can also cause long-term lumbar pain, abdominal pain and other problems. In addition, gynecological examination can also be the menstrual shedding of endometrial debris into the uterine muscle wall, fallopian tubes and even the pelvis, resulting in endometriosis, causing gradually aggravated dysmenorrhea. When persistent irregular vaginal bleeding occurs, or sudden heavy bleeding accompanied by abdominal pain, fainting, or the appearance of a mass, one should not mechanically wait until after the menstrual period has cleared in order to avoid delaying the condition. Patients are advised to wash the vulva with water before visiting the clinic, and should avoid sexual intercourse as well as vaginal medication the day before so as not to affect the results of laboratory tests. Preparation for tubal patency test, IUD or removal of contraceptive ring, cervical treatment, hysteroscopy, etc. should be carried out 3 to 7 days after the menstrual period is clean and intercourse is prohibited from after the menstrual period to before the test to prevent infection. And when infertility patients check whether ovaries are ovulating to do diagnostic scraping, the endometrium should be scraped 12 hours before predicted menstruation or 12-24 hours after menstruation, not after menstruation. Those checking for pregnancy without abdominal pain or vaginal bleeding should have an ultrasound around 50 days after menopause to find out the time of implantation and to rule out ectopic pregnancy. In conclusion, the diagnosis and treatment of different diseases, different methods, need to choose a different time, the patient needs to have some understanding, but also to follow the doctor’s arrangement.