A method for two-node cluster hot backup, comprising: configuring, by a second network node, a redundancy protocol with a first network node at an access port of the second network node to negotiate an active/standby relationship between each local access port of the second network node and each access port of the first network node; advertising, by the second network node, a route of a network segment of a user, wherein the network segment of the user is the same as a network segment of a user to which a route advertised by the first network node belongs; establishing or specifying, by the second network node, a protection channel with the first network node; synchronizing, by the second network node, user information with the first network node; and when an access link or an access port of the user of the first network node has a failure, performing, by the second network node, service switching according to the redundancy protocol, and sending, by the second network node, downstream traffic to the user according to the user information; wherein, if the downstream traffic arrives at the first network node, receiving, by the second network node, the downstream traffic from the first network node through the protection channel, and sending, by the second network node, according to the user information, the downstream traffic to the user through the access port determined through negotiation and according to the redundancy protocol; if the downstream traffic arrives at the second network node, sending, by the second network node, according to the user information, the downstream traffic to the user through the access port determined through negotiation and according to the redundancy protocol. configuring, by a second network node, a redundancy protocol with a first network node at an access port of the second network node to negotiate an active/standby relationship between each local access port of the second network node and each access port of the first network node; advertising, by the second network node, a route of a network segment of a user, wherein the network segment of the user is the same as a network segment of a user to which a route advertised by the first network node belongs; establishing or specifying, by the second network node, a protection channel with the first network node; synchronizing, by the second network node, user information with the first network node; and when an access link or an access port of the user of the first network node has a failure, performing, by the second network node, service switching according to the redundancy protocol, and sending, by the second network node, downstream traffic to the user according to the user information; wherein, if the downstream traffic arrives at the first network node, receiving, by the second network node, the downstream traffic from the first network node through the protection channel, and sending, by the second network node, according to the user information, the downstream traffic to the user through the access port determined through negotiation and according to the redundancy protocol; if the downstream traffic arrives at the second network node, sending, by the second network node, according to the user information, the downstream traffic to the user through the access port determined through negotiation and according to the redundancy protocol.