A routing table management method, characterized by comprising: creating a next hop information index table in a host router; and constructing a correlation between the host router and next hop information corresponding to the host router according to a specific index in the next hop information index table; pointing a subnet router to a corresponding host router, wherein the next hop of the subnet router is a host router, acquiring a next hop information index table from the host router; and constructing a correlation between the subnet router and next hop information corresponding to the subnet router according to a specific index in the next hop information index table; each specific index in the next hop information index table containing port information, destination MAC replacement information, source MAC information and Virtual Local Area Network, VLAN, information of the corresponding next hop information, the method further comprising: when the next hop of the subnet router is changed to pointing to host router B host from initially pointing to host router A, finding a specific index of the egress table of host router B and assigning the specific index of the egress table of host router B to the subnet router, and wherein the egress table is a next hop information index table, which is aggregated and organized with the next hop information to which the host router B points; and the specific index contains all information about the next hop of host router B. creating a next hop information index table in a host router; and constructing a correlation between the host router and next hop information corresponding to the host router according to a specific index in the next hop information index table; pointing a subnet router to a corresponding host router, wherein the next hop of the subnet router is a host router, acquiring a next hop information index table from the host router; and constructing a correlation between the subnet router and next hop information corresponding to the subnet router according to a specific index in the next hop information index table; each specific index in the next hop information index table containing port information, destination MAC replacement information, source MAC information and Virtual Local Area Network, VLAN, information of the corresponding next hop information, the method further comprising: when the next hop of the subnet router is changed to pointing to host router B host from initially pointing to host router A, finding a specific index of the egress table of host router B and assigning the specific index of the egress table of host router B to the subnet router, and wherein the egress table is a next hop information index table, which is aggregated and organized with the next hop information to which the host router B points; and the specific index contains all information about the next hop of host router B. when the next hop of the subnet router is changed to pointing to host router B host from initially pointing to host router A, finding a specific index of the egress table of host router B and assigning the specific index of the egress table of host router B to the subnet router, and wherein the egress table is a next hop information index table, which is aggregated and organized with the next hop information to which the host router B points; and the specific index contains all information about the next hop of host router B.