Iridium on alumina catalyst is mainly used for catalytic decomposition of single-component propellant hydrazine in attitude control engines of space satellites ‌.In addition, the iridium alumina catalyst shows high efficiency in the chemical reaction and can promote the efficient chemical reaction. Iridium catalyst plays an important role in promoting organic synthesis. Among them, the most important is its application in the field of asymmetric synthesis. Iridium catalyst can catalyze asymmetric hydrogenation reaction, asymmetric amination reaction, asymmetric alkylation reaction, so that the synthesized compounds have high stereoselectivity, thus improving the synthesis efficiency and yield. Iridium catalyst has been widely used in energy conversion field. Among them, the most important is its application in the field of fuel cells. Iridium catalyst can be used as cathode catalyst of fuel cells to promote oxygen reduction reaction, thus improving the efficiency and stability of fuel cells. Iridium catalyst also has important application value in the field of environmental protection. Iridium catalysts can catalyze the oxidation of organic waste gas, converting organic waste gas into harmless carbon dioxide and water. Iridium catalysts can also catalyze key reactions in wastewater treatment processes, degrade organic pollutants, and purify wastewater.