In the future urban transportation, the unmanned transportation system will play an increasingly important role as the central command and control of unmanned transportation units in smart cities. The author believes that the unmanned transportation system includes at least decision control subsystems, equipment management subsystems, encryption communication subsystems, intelligent rescue subsystems, and unmanned transportation tool subsystems. The unmanned transportation system comprehensively processes all key information of the entire transportation system, effectively organizes the normal operation of transportation tools, and controls its own development. The unmanned transportation system has characteristics such as evolution, generalization boundary, automatic prediction and processing of changes, and emphasis on uncertainty. This paper systematically explores the information processing mechanism of the unmanned transportation system and proposes a more feasible information processing method for each link, which to a certain extent contributes to the stable and efficient operation of the future system.