Abstract: When the freight car follows the train to the marshalling station, it is usually necessary for the disintegration and marshalling operations. The different transit modes of freight car have a great influence on calculating the parking time. Based on the analysis of the main contents of the freight car formation plan, the data table of the direct train and the train data table are sorted out. In the calculation of a single vehicle, first of all, this paper analyzed the through marshalling station string in the vehicle routing scheme, then, according to the train data table, determined whether the train was a direct train. For a direct train, the through marshalling station was treated as non shunting operation. Based on the train data table, a recursive decision algorithm was designed to determine the transit mode of freight car passing through the marshalling station. Using this method, people could quickly determine the transit mode of freight cars in marshalling station, which made the calculation results more quickly and accurately.