Abstract: By studying the communication mechanism of WTB bus, the problem of low bandwidth utilization of WTB bus was solved. The gateway software programing for WTB bus data communication was proposed by using TCN message communication mechanism and process data communication mechanism. The calculation and analysis of communication time and experimental verification of the data amount transmitted by WTB bus showed that the communication mode increased the data amount transmitted by WTB bus in the basic communication cycle, and improved the bandwidth utilization of WTB bus. The gateway programming method of TCN message and process data reduced the transmission delay of large capacity data on WTB bus, reduced the complexity of program development and ensured the reliability of train network system.