If the smell is very big once you have intercourse, the most common clinical reason is that the dysbiosis in the vagina leads to anaerobic bacteria flourishing, and the Gardnerella infection leads to bacterial vaginosis, so there will be a big fishy odor. In this case, we should pay attention to the following points clinically: First, both husband and wife should pay attention to the hygiene of sexual life and wash the external genitalia before intercourse to reduce the possibility of pathogenic bacteria infection. Second, if the male partner has a long foreskin, it is recommended to turn up the foreskin before sex and clean the foreskin scale before having sex, which also reduces the possibility of infection. The main purpose is to improve the local resistance in the vagina, regulate the normal flora in the vagina and reduce the possibility of anaerobic bacterial infection.