What is called fairy worm in the new edition of materia medica is cicada slough. Mainly because in the ancient concept, cicada slough has special reproductive ability and vitality. Although seemingly lifeless, in fact, it has infinite vitality and energy inside. In addition, the molted cicada is regarded as a precious animal product because of its dry, shiny and beautiful appearance, so it is endowed with the attribute of "fairy". At the same time, cicada slough is bitter in taste and flat in nature, and has the effects of clearing away heat and toxic materials, calming the liver and calming the wind. In traditional Chinese medicine, it is often used as a medicine to treat hypertension, insomnia, epilepsy and other diseases, so it is also widely used.