Abstract: For the demand of an on-board communication platform for high-speed maglev trains, a plan based on RTLinux (real-time linux) was proposed, including the architecture design of the communication platform based on RTLinux, the designs and realizations of real-time and non-real-time processing modules. The driver program of RTLinux for CPCI-CAN (compact peripheral component interconnect-control area network) board was given and realized through the discussion of program development. In addition, the real-time performance of the communication platform of the diagnosis system was analyzed by virtue of the dispatch time model and the transmission delay model. The real-time simulation results show that the mean update time of all network nodes in the communication platform is 290 ms to meet the real-time demand (the response time should be less than 500 ms) for a high-speed maglev train.