Abstract In order to solve the media contention problem of train switched Ethernet and improve the real-time performance of train communication network, this paper conducts real-time research on the access mode of terminal equipment of train communication network. Through the time division multiplexing mechanism, the network bandwidth is allocated according to the data type, and a bandwidth allocation strategy based on temporal constraints is established. It mainly schedules the time slots of real-time periodic data, and obtains a static schedule of multiple tasks based on the temporal constraints, so that the terminal equipment can receive the static schedule in the initial stage of the system. Each terminal device sends data in the specified time slot according to the static schedule to avoid the collision of network data frames, and at the same time reserve more bandwidth for the transmission of real-time aperiodic data, ensuring the real-time and reliability of train communication network.