The invention discloses a VPRP based backup system and method. A master router and backup routers are selected from routers in advance, each of the master and backup routers includes a weight value and VLAN (Virtual LAN) with the same routing path, one of the VLAN is selected as a communication representative, a communication representative of the master router transmits an advertisement packet to a communication representative of the backup router continuously, an ARP (Address Resolution Protocol) table is transmitted to the backup router continuously, and when the communication representative of the backup router does not receive the advertisement packet, it is determined that all VLAN of the master router are abnormal and the master router is replaced. Thus, the backup switching efficiency as well as the number of available VLAN is improved.