Dark menstrual blood is not necessarily a precursor of cervical cancer. Normal menstruation starts with a small amount and is coffee-colored, during menstruation it is bright red and more voluminous, and eventually it may become less voluminous, coffee-colored or even black. The black color of menstrual blood is usually a sign that the blood stays in the reproductive tract for too long, which is not related to cervical cancer. Bleeding of cervical cancer manifests as contact bleeding, the amount may be more or less, the color is darker, coffee-colored or even black. Patients with advanced stage of cervical cancer have more secretions, and the odor is very serious, which will have a fishy smell. The color of menstruation alone cannot determine whether the patient has a tumor or not. To diagnose cervical cancer, it is necessary to undergo cervical cancer screening, including TCT, HPV examination, and biopsy of diseased tissues through colposcopy, which is the gold standard for diagnosing cervical cancer. Patients are advised to undergo regular cervical cancer screening, maintain good hygiene and living habits, and consult the doctor promptly if they feel unwell.