Abstract: Passenger information system of CRH5 EMU has been used for many years. Its performance and functionality is difficult to meet the growing application demand. This article presented a design concept and implementation scheme for a new type of passenger information system management unit(PMU), introduced the system principle and function division, analyzed key technologies involved in the hardware and software, and described the optimization and promotion in functions of the PMU. The new PMU has been installed in the CRH5 EMU, obtained good feedback.