Abstract: In view of the fact that the information received by the marshalling yard's field crew was not consistent with the actual situation and the operational efficiency was not high, this paper put forward a solution to the field mobile system in marshalling yard. Taking the operation management process of marshalling yard as a trend, combining with McWiLL wireless communication system technology and intelligent handset, the mobile system of marshalling yard was designed by setting up core network equipment and wireless network base station. The system had functions such as field staff's handset login, identity confirmation, handset dispatching, data transmission, voice calling, photo uploading, post operation mobile processing, information real-time uploading and so on. The application results in Lanzhou North Marshalling Yard show that the system implements paperless and digitalized office work for field worker and improves the labor intensity of field workers.