Cactus applied externally has the effect of reducing swelling and relieving pain, and can be used as an adjunctive treatment for carbuncle boils and sores. Cactus is a traditional Chinese medicine with a bitter taste and cold nature. For people with canker sores and ulcers, peel the cactus, mash it into a paste and apply it to the affected area. Applying cactus externally can bring out its effect of clearing heat and removing toxins (removing heat and toxicity from the body), which is conducive to the elimination of redness and swelling and promotes the healing of the skin. Cactus can also be used as a pain reliever for canker sores and ulcers. Although the external application of cactus has more effects, but some people may have allergies to cactus, if the use of the process of discomfort, should be immediately discontinued, and wash clean. In addition, the external application time should not be too long, the external application should be kept clean and dry skin after the end. It is recommended to use under the guidance of a doctor’s diagnosis, do not blindly apply external compresses, so as not to aggravate the condition.