The systematic theoretical research on liquid ammonia finishing began in 1930s and was put into industrial production in 1970s. At first, the liquid ammonia processing technology was jointly developed by Texaco University in Norway and Norwegian Central Industrial Research Institute in 1963. At that time, yarn finishing was used instead of yarn mercerization. Due to the strong permeability of liquid ammonia to cotton fiber, the residual liquid ammonia on yarn is easier to remove than alkali liquor, and the mercerizing effect is better than alkali liquor, so it has attracted much attention. 1968 After Sanfu Company of the United States obtained the patent, Sanfu pure cotton denim (Sanfor-set) brand appeared, and jeans with stable size and soft touch were all the rage. But in the 1970s and 1980s, on the one hand, synthetic fibers developed rapidly, and all kinds of polyester-cotton products on the market were easy to wash and dry, which were deeply appreciated by consumers. On the other hand, with the trend of returning to simplicity and naturalness, pure cotton fabrics are quite popular among the public. Liquid ammonia finishing is mainly used for finishing heavy denim fabrics in the United States. Liquid ammonia finishing process is complex, ammonia recovery rate is high and the cost is very expensive. Therefore, the popularity of domestic and foreign markets has slowed down several times. Later, at least seven liquid ammonia finishing equipments were put on hold in the United States, and one was moved to Thailand. During the 1980s, liquid ammonia finishing was really silent in domestic and foreign markets for more than ten years. Until 1990s, in order to start the market and develop products, some Japanese enterprises made great efforts to innovate and improve resin finishing technology on the basis of liquid ammonia finishing equipment, and actively developed setting finishing technology combined with liquid ammonia finishing. Although they failed many times, in the end, at 1993, Nissin Spinning introduced super-soft finishing (S.S.P) and Toyo Spinning also introduced steam finishing (V.P.). At this time, almost half of the shirts in the pure cotton non-ironing finishing products produced in the Japanese market have to be finished in a stable form. These processes are based on liquid ammonia finishing and then resin finishing, which set off a wave of form stabilization finishing in the market. Japan's Kyoto Machinery and Shandong Iron Works have been able to provide liquid ammonia finishing machines, and Maekawa Plant and Iwatani Industry have been able to provide supporting ammonia recovery devices. At this time, the United States seems to have forgotten the liquid ammonia finishing, while Japan has revived the liquid ammonia finishing technology.