Realgar has the effects of detoxification and insecticide,dampness and expectorant and malaria,and is suitable for a variety of diseases,and is mainly used for the treatment of carbuncle boils,snake bites,abdominal pain,epilepsy and malaria.Modern studies have shown that realgar has a good therapeutic effect on hematologic diseases,malignant lymphatic diseases and solid tumors,especially for leukemia.As a toxic arsenic-containing mineral drug,realgar can not be ignored if used improperly.Realgar is a component of soluble arsenic that has a therapeutic or toxic effect,including inorganic arsenic and organic arsenic.Realgar has central nervous system toxicity,hepatotoxicity and genotoxicity,and reasonable compatibility can reduce the toxicity of realgar.Processing has an impact on the toxicity of realgar,and the toxicity of realgar processed by the water fly method is even lower,and some researchers have used new technologies such as microbial transformation and nanotechnology to study the toxicity of realgar.In this paper,the toxicity of realgar is reviewed,in order to provide a theoretical basis for the safe and rational use of realgar.