A method for rebuilding single ring network topology, comprising: each node in a single ring network detecting, at a predetermined time interval, whether a link connected with a root port of the node is failed; when one node in the single ring network detects the link failure, the node having a blocking port obtaining information that the link failure occurs in the single ring network; the node having the blocking port switching a state of the port from a blocking state to a forwarding state; wherein the step that the node having the blocking port obtaining the information that the link failure occurs in the single ring network comprises: the node having the blocking port detecting that the link connected with the root port of the node is failed; or a node having a non-blocking port detecting that the link connected with the root port of the node is failed; the node having the non-blocking port transmitting a self-defined bridge protocol data unit (BPDU) message through a designated port to a next node, if the next node has not a blocking port, then the next node make a max age timer expired after receiving the self-defined BPDU, this transmission process is repeated until the node having the blocking port receiving the BPDU message and acquiring the information that the link failure occurs in the network for any one node in the single ring network, when the port state of the node changes, the state conversion process is that: the blocking state is directly switched to a forwarding state through a listening state. each node in a single ring network detecting, at a predetermined time interval, whether a link connected with a root port of the node is failed; when one node in the single ring network detects the link failure, the node having a blocking port obtaining information that the link failure occurs in the single ring network; the node having the blocking port switching a state of the port from a blocking state to a forwarding state; wherein the step that the node having the blocking port obtaining the information that the link failure occurs in the single ring network comprises: the node having the blocking port detecting that the link connected with the root port of the node is failed; or a node having a non-blocking port detecting that the link connected with the root port of the node is failed; the node having the non-blocking port transmitting a self-defined bridge protocol data unit (BPDU) message through a designated port to a next node, if the next node has not a blocking port, then the next node make a max age timer expired after receiving the self-defined BPDU, this transmission process is repeated until the node having the blocking port receiving the BPDU message and acquiring the information that the link failure occurs in the network for any one node in the single ring network, when the port state of the node changes, the state conversion process is that: the blocking state is directly switched to a forwarding state through a listening state. the node having the blocking port detecting that the link connected with the root port of the node is failed; or a node having a non-blocking port detecting that the link connected with the root port of the node is failed; the node having the non-blocking port transmitting a self-defined bridge protocol data unit (BPDU) message through a designated port to a next node, if the next node has not a blocking port, then the next node make a max age timer expired after receiving the self-defined BPDU, this transmission process is repeated until the node having the blocking port receiving the BPDU message and acquiring the information that the link failure occurs in the network for any one node in the single ring network, when the port state of the node changes, the state conversion process is that: the blocking state is directly switched to a forwarding state through a listening state.