分析了三氧化硫在甲苯法己内酰胺生产中的重要作用,通过对影响预混合反应和酰胺化反应的各路进料性质的分析,提出了影响反应的关键因素是循环轻相带水和亚硝基硫酸中三氧化硫波动,分析了亚硝基硫酸制备单元和酰胺化单元的操作参数、现象,并结合实验室试验,逐步提出了相应的多项解决措施,使装置实现了长期稳定运行,各项消耗数据良好,提高了装置收率和平稳率.“,”The important role of sulfur trioxide in caprolactam production by toluene method was anaylzed. The various material properties change of influencing premixed and amidation were analyzed.The main key factors affecting reaction were circular light phase with water and nitroso sulfur trioxide in sulfuric acid,sulfuric acid and the nitroso preparation unit and amidation unit of each unit operation parameters,the phenomenons were analyzed,and combining with laboratory experiments,the corresponding multiple solutions were gradually put forward,so the devices were in the secure full of cycle and stable operation,the consumption data were good,the unit yield and the smooth rate were improved.