The invention relates to a communication method and device. The method and the device are applied to a satellite system comprising a master control node and a plurality of controlled nodes. The method is applied to the master control node. The method comprises the steps of sending roll call information to the controlled nodes through buses connected with the controlled node; in a first preset time period after the roll call information is sent, judging whether the buses used for transmitting the roll call information receive first data packets sent by the controlled nodes or not; if the first data packets are received, judging whether destination addresses are the addresses of the master node or not; if the destination addresses are not the addresses of the master node, judging whether the destination addresses and source addresses are located on the same bus or not; and if the destination addresses and the source addresses are not on the same bus, forwarding the first data packets to the target buses corresponding to the destination addresses. According to the method, the master control node is equivalent to a control hub and can coordinate the data packets uploaded by the different controlled nodes, and when the data packets need to be forwarded, the data packet can be forwarded among different buses.