The most common clinical cause of sour smell in leukorrhea is due to local inflammation of the vagina, commonly caused by anaerobic bacterial infection. It is recommended to have a gynecological examination to find out whether the vaginal mucosa is congested, edematous and other inflammatory manifestations; it is recommended to have a routine laboratory test of the leukorrhea and give medication according to the pathogenic bacteria of the infection. If the leukorrhea has a sour smell, it is also recommended to exclude the possibility of local inflammation of the cervix, because local inflammation of the cervix can lead to an increase in glandular secretions, which can cause an increase in leukorrhea, and when combined with inflammation, it can cause symptoms of odor. It is recommended to do cervical duct secretion test and cervical cancer screening, mainly to exclude cervical epithelial lesions or whether there is high-risk HPV infection in the cervical epithelium.