The embodiment of the invention provides a network system and a method for realizing network fault recovery by means of shared standby routers. The method for realizing network fault recovery by means of shared standby routers comprises the following steps: when a first access router senses that the first transmission router connected with the first access router breaks down, a target shared standby router is confirmed from each one of the shared standby routers to replace the first transmission router; then the first access router uses the target shared standby router as a intermediate route node to calculate the work routing path between the first access router and the first interconnection router corresponding to the first access router as the first routing path based on the address information of the target shared standby router; then the first access router transmits the route information of the first routing path to the other routers in the first routing path; and finally, the first access router and the other routers in the first routing path forward the target data flow according to the first routing path. According to the scheme, the number of shared spare routers is low, therefore, the cost of the whole network system is low.