For the limitation of MVB cards in railway only adapting in MVB-cPCI or MVB-PC/104 bus, a new communication method was given, by detecting buses connecting status with ARM microprocessor, automatically loading different procedures upon FPGA, to realize the interconnection of MVB communicate with other system buses (such as MVB-USB, MVB-Ethernet bus, etc.) by the universal MVB interface unit. With the designed universal MVB interface, application range of MVB cards extended, and compatibility of on-board devices was enhanced. Interface design of multiple system buses connection based on FPGA was expounded theoretically, and the prototype was realized and tested, which showed that this study could be used to develop the high-rate-communication devices of TCN5.