Cupping is a treatment method that uses a jar as a tool to remove air from the jar by burning fire and pumping, causing negative pressure to adsorb on the corresponding points on the body surface to prevent disease and cause illness. Usually, cupping shoulder black is a normal phenomenon, usually due to negative pressure caused by the rupture of capillaries, but if it does not recede for a long time, you need to consider the cupper improper operation caused. The adsorption effect of cupping causes the rupture of capillaries in the muscle surface area, followed by local blood clotting, and the appearance of the shoulder area will be found to appear black and purple. Generally, it can be absorbed and fade away within a week. If the skin blackening phenomenon does not subside for a long time, it may be caused by improper cupping operation. If the cupping time is too long, resulting in excessive local bruising and swelling of the skin, excessive blackening of the skin, or black purple does not fade easily, or even blisters and ulcers appear. In addition, if cupping is too strong and exceeds one’s own capacity, in addition to skin blackening, it may also cause skin breakage, resulting in skin infection, and in those who have a tendency to bleed or are physically weak, it may also cause bleeding and other symptoms. If a patient needs cupping, he or she should choose it under the guidance of a professional doctor, taking into account the therapeutic effect and the patient’s own ability to tolerate it. Do not operate blindly at home to avoid improper operation, resulting in the above-mentioned adverse consequences.