The possible causes of urinary tract infection after intercourse: first, the intercourse did not do a good job for the local cleaning of the genitals, in the process of intercourse, causing the local skin of the external genitalia of the colonized bacteria into the urethra and caused the patient’s infection. Secondly, the time of intercourse is too long and can cause mucosal congestion or erosion, which may lead to a higher incidence of infection. Thirdly, one of the partners has a chronic infection, so in the process of intercourse, there will be aggravation of the infection or cause each other’s infection, which is more likely to have a urinary tract infection. Especially some special pathogenic infections, such as gonococcus, mycoplasma, chlamydia, after intercourse, soon the partner can appear the same symptoms of infection. Fourth, if the woman has a gynecological disease, the process of intercourse may lead to a male partner with a urinary tract infection. It is advisable not to have intercourse before the gynecological disease is cured, so as not to cause repeated infections.