Aiming at shortening new product lead time,diagnosing the bottlenecks,improving equipment efficiency of multi-function track beam production line(MTBL) in iron&steel companies,the characteristics of MTBL,which is different from the traditional discrete or process manufacturing production,is analyzed.Based on characteristics research,the Petri network model of MTBL and the Component-based simulation models of rolling mills constructed,and then MTBL simulation system is developed.Tthe validity and practicability of simulation system are well verified by a case study in a iron&steel company.