The chemical name of alum is potassium aluminum sulfate dodecahydrate, which is a compound salt of potassium sulfate and aluminum sulfate containing crystalline water, and is generally colorless and transparent. The antibacterial and astringent effect of alum can be used as traditional Chinese medicine. Alum can be used externally to detoxify, kill insects, dry dampness and relieve itching, and internally to stop bleeding, stop diarrhea and resolve phlegm, so it is used to treat insect and snake bites, itchy skin, scabies and eczema, and alum solution soaking feet can treat foot hyperhidrosis and foot odor. Alum has antibacterial and astringent effects, alum is a broad-spectrum antibacterial, and has different degrees of antibacterial effects on a variety of bacteria, ringworm and candida. Alum can strongly coagulate proteins, and clinically it can also be used as an anti-inflammatory, hemostatic, anti-sweat, anti-diarrheal, and as a sclerosing agent. The hemostatic effect of alum, alum is astringent in nature and has astringent and hemostatic effect, which can cure many kinds of bleeding diseases, such as blood in stool.