The invention discloses a cross-segment message forwarding method for dispatching automation systems. Message forwarding servers of a transmitting end system and a receiving end system all adopt dual redundant configurations, and the two computers are operated in a mode of a master computer and a slave computer; a wide area dual-network redundant configuration is adopted between the transmitting end system and the receiving end system, and each message forwarding server is connected with the wide area dual-network; while the transmitting end system performs one-way message forwarding to the receiving end system, the receiving end system does not transmit a feedback message to the transmitting end system. The message forwarding method of the invention meets the high-performance high-reliability real-time requirements on message forwarding of the dispatching automation systems among different network segments so as to further ensure the uniqueness of the message.