Dry powder fire extinguisher is a kind of fire extinguisher, which can be divided into: ① ordinary dry powder fire extinguisher; ② Ultra-fine dry powder fire extinguisher. The dry powder fire extinguisher is equipped with ammonium phosphate and other dry powder fire extinguishing agents. This dry powder fire extinguishing agent is easy to flow and dry. It is composed of inorganic salt and crushed dry additives, which can effectively put out the initial fire.