The present invention relates to the field of communications on rail trains. A PicoBlaze-based MVB controller includes a pMVB controller, a traffic memory, an ARM adapter, and a bus arbiter. The pMVB controller, the traffic memory, ARM adapter, and the bus arbiter are connected to an external bus BUS1. The pMVB controller is connected to the traffic memory. The ARM adapter is connected to an external ARM processor and the bus arbiter. The traffic memory can store network communication data and input control information, and send them to the pMVB controller. The pMVB controller responds to the control information, and sends the communication data, and after it is encoded, to the MVB bus via the external bus BUS1. The pMVB controller also decodes data received from the pMVB bus and triggers an interrupt. The bus arbiter is responsible for bus arbitration in accordance with the instructions from the pMVB controller.