Vulvar pain after coitus can be caused by a number of reasons. First, excessive friction of the vulva, including the vagina, will cause edema of the vaginal mucosa, which will cause pain. Secondly, if the coitus is very violent, it will cause the destruction of local blood vessels, which will also cause local edema, and will cause pain. Third, when there is vaginal inflammation, the inflammation itself coupled with coitus, it may lead to aggravation of the stimulus, can cause vulvar pain. In this case, you can first go to the pharmacy to buy lotion, such as gynecological cleaning or Cleanse, with 1:10 water for a bath, sit in the bath for 15 minutes. Then you can smear erythromycin ointment on the vulvar opening, you can observe for 3-7 days, if the symptoms get better will not affect the health of the body, and in the future, you must be gentle when having sex.