PH monitoring is mainly to detect the acidity or alkalinity of fluids. In medicine, it is commonly used in medical examinations such as human urine and vaginal secretions, or amniotic fluid in pregnant women, and is one of the commonly used tests to determine if the vaginal flora of a woman is out of whack. PH monitoring is primarily used to measure the activity of hydrogen ions in a solution to determine the acidity, neutrality and alkalinity of the solution. Normally, estrogen in a woman’s body, along with the lactobacillus bacteria in the vagina, keep the vagina in an acidic environment. This acidic environment can effectively inhibit the reproduction of pathogenic bacteria and play a self-purifying as well as sterilizing role in the reproductive system. The PH test can help to detect the PH value in a woman’s vagina. When inflammation occurs in the female reproductive tract, the acidic and alkaline environment in the vagina may change. Therefore, through the PH test, the acidity and alkalinity of the environment in the female vagina can be confirmed, so as to determine whether there is inflammation in the vagina. If there is a significant change in the PH value, it is recommended that the patient go to the relevant department of the hospital for an examination in a timely manner and follow the doctor’s instructions to clarify the cause of the disease and target treatment.