Melanin on the neck of fat people may be caused by excessive friction, acanthosis nigricans, etc. It can be removed with the help of enhanced care, medication and medical treatment. 1. Excessive friction: the skin folds on the neck of fat people are relatively more than those of thin people, and the long-term friction and stimulation of the local skin folds will make the skin melanocyte hyperfunction, which will lead to melanin precipitation. Such patients can be applied locally to promote the metabolism of skin melanin, and severe cases can also be used to help lighten melanin through intense pulsed light, pigmented pulsed laser and other medical methods. 2. Acanthosis nigricans: Some obese patients will suffer from benign acanthosis nigricans, which manifests the symptoms of darkening of the skin color in the neck, armpits, groin and other parts of the body, and there are velvety protrusions on the surface of the skin at the same time. Patients can apply topical retinoic acid gel, hydroquinone cream, cod liver oil ointment and other ointments to help remove melanin precipitation, and severe cases also need to take oral vitamin A to help treatment. In addition, both types of patients need to pay attention to strengthen exercise, weight control; light diet, can eat more vegetables and fruits rich in vitamin C, vitamin E; pay attention to strengthen the neck area of the sun when going out, etc., so as to help better remove the melanin on the neck. The use of the above drugs need to follow the doctor’s instructions, it is recommended that patients timely to the hospital, under the guidance of the physician for standardized treatment, to avoid the occurrence of adverse reactions.