Black hair on the face is usually caused by polycystic ovary syndrome or genetic factors, and can be removed through medication or physical therapy. 1. Polycystic Ovary Syndrome (PCOS): Black hair on the face due to excessive androgens, and may be accompanied by menstrual disorders, acne, obesity and other symptoms. Patients can follow the doctor’s instructions oral anti-androgen drugs such as spironolactone for treatment. 2. Hereditary factors: due to genetic factors or personal physical reasons leading to the growth of body hair, the face of long black hair, can be treated with laser hair removal, generally can achieve the effect of permanent hair removal. In addition, you can also use a razor to shave off the black hair, but usually can not be cured. If a large number of black hairs appear in a short period of time, it is necessary to go to the hospital in time for examination, to clarify the specific causes of the disease, and standardized treatment under the guidance of the doctor.