Red salve, also known as red mercury, is a kind of disinfectant and antiseptic drug with bactericidal and antibacterial effects and is less irritating. It is suitable for disinfection of small skin wounds and mucous membrane wounds, skin disinfection before surgery, quinturology and minor operations, and disinfection of the urethra. Note that because of its weak penetrating power, the antibacterial effect is effective and is currently used relatively little in clinical practice to avoid infection due to incomplete disinfection. Because red salve contains mercury, it cannot be used at the same time with tincture of iodine to avoid chemical reaction between the two, which may cause damage to skin and mucous membrane. In addition, because of the slight toxicity of red salve, it is not recommended to use it when there are large burns, skin or mucous membrane septic infection. During the storage process, red potion is easily affected by carbon dioxide in the air and produces precipitation, so it should be kept in a sealed place, and once precipitation occurs, it is not recommended for use. Therefore, red salve is currently used in a limited clinical application, the use of clear indications and attention to contraindications.