The most common reason is due to anaerobic infection, such as Gardnerella infection can lead to vaginal discharge odor, mainly because this bacterial infection will produce a large amount of ammonia in the vagina, so there will be a fishy odor, through the use of medication to treat the majority of this symptom will disappear. Secondly, girls who have sex history may have endometrial cancer or cervical cancer, which may lead to the odor of secretion, mainly because when combined with infection or necrosis of cancerous tissues, it will lead to odor of secretion, so it is recommended to go to the hospital as soon as possible for checkup, and then give medication according to the result.