No-feedback safe isolation and information one-way transmission system and double-machine backup method

The invention discloses a no-feedback safe isolation and information one-way transmission system and a double-machine backup method. The system comprises a data sending-end module, a data receiving-end module and no-feedback safe isolation and information one-way transmission devices, wherein the two devices are connected by use of a special-purpose data line. When a fault is detected in a fault detection circuit of the device at a working state, a control module is notified, the control module firstly closes a power supply of a data transmission module in the device, then notifies the device at a backup state through the special-purpose data line to enable the device at the backup state to enter a working state, then emits alarm information, is accessed to the system after fault repair and is started after being accessed to the special-purpose data line between the two devices, and the device is about to enter a backup state at the moment. Data sending-end software and data receiving-end software can automat