When there is a fishy smell in the vagina, it is usually caused by bacterial vaginitis, often combined with trichomoniasis, and requires targeted treatment based on pathogenic examination of vaginal secretions.1. Bacterial vaginitis: often caused by disorders of the normal flora in the vagina, mainly Gardnerella and Bacteroides actinomycetemcomitans, mainly anaerobic bacteria, vaginal secretions often have a fishy smell, accompanied by vulvovaginal itching and burning sensation, treatment can be Metronidazole and tinidazole can be used systemically, together with metronidazole vaginal suppositories and clindamycin ointment for topical application, which need to be applied in full and in sufficient quantity under the guidance of a doctor. During menstruation, oral medication can be used and suppositories can be stopped. It is usually curable, but the disease has a high recurrence rate. 2. Trichomonas vaginitis: It often exists along with bacterial vaginitis, mainly because of the disturbance of the vaginal environment, change of pH and proliferation of trichomonas, often manifested as purulent, yellowish-green vaginal discharge with a foul odor, and some patients have painful intercourse. Patients can apply systemic antibiotics such as metronidazole under the guidance of doctors, and can use acidic solutions such as acetic acid to cleanse the vagina at the same time to promote the recovery of vaginal environment. 3. Cervical cancer: In rare cases, the fishy odor of vagina does not exclude the possibility of cervical cancer, and patients with advanced cervical cancer can have fishy odor of vagina when they have concurrent infection, usually accompanied by purulent discharge, abnormal vaginal bleeding and other symptoms, which may require Surgery and radiotherapy may be required.