This paper begins with a description of the complexity of making up freight train marshalling
plans. It is pointed out that an exact and rational result can be obtained by joint optimization of car flow
routing and marshalling plan. Then, a mathematical model is built by transforming the problem of freight
train marshalling plan into a calculation problem aboutmarshalling network graph, tominimize the total cost
of car flows within the railway network. Finally, the algorithm of this model is approached.