The disclosure relates to a fault-tolerant method and apparatus for a network device system, a computer device, and a storage medium. The method includes: when the link state changes, the source switch acquires and transmits link state change information to the master controller, randomly selects a switch from the first switch unit or the second switch unit, and transmits a copy of the link state change information to the selected switch; such that the master controller forwards the link state change information to the second switch unit, the auxiliary controller receives the copy of the link state change information transmitted by the switch selected by the source switch and transmits it to the second switch unit; after the second switch unit updates the local routing table according to the acquired information, the master controller transmits confirmation information to the source switch.