If a woman’s underwear is yellow and has a bad odor, it is clinically due to the following reasons: first, if the discharge is yellow and has a fishy odor, it may be clinically due to bacterial vaginosis caused by anaerobic infection. Secondly, if the underwear is yellow and the discharge has a strong odor, it is clinically likely to be caused by cervical cancer or endometrial cancer. It is recommended to do gynecological examination as well as cervical cancer screening, mainly TCT and HPV tests, and ultrasound is recommended to find out whether there are abnormal echoes in the endometrium. If the cervical cancer screening is fine and the endometrial examination is also fine, it is recommended to actively treat the local inflammation of the vagina, and if there is any problem, it is recommended to give appropriate treatment according to the specific situation.