Pi nitrate in traditional Chinese medicine is called “manganite”, in accordance with the theory of traditional Chinese medicine, Pi nitrate cold, salty taste, bitter. Mainly into the large intestine, stomach meridian. It has the effect of moistening dryness and softening, clearing fire and swelling, laxative and laxative. Clinical can be used for 1, solid heat blockage of the large intestine caused by dry stool, abdominal pain and fullness, etc. 2, intestinal carbuncle abdominal pain. 3, breast carbuncle, hemorrhoids, sore throat, mouth and tongue sores, etc., the main component of the skin nitrate for sodium sulfate, and a small amount of sodium chloride, magnesium sulfate, calcium sulfate, and so on. Modern pharmacological studies have confirmed that it has the effect of promoting intestinal peristalsis and diarrhea. PiNi bitter cold, pregnant women should be used with caution. According to the theory of “eighteen against nineteen fear”, PiNi should not be used with sulfur, trigonometry. PiNi is generally not included in the decoction, and is used externally in moderation.