A control method for protecting connectivity between Ethernet ring network nodes including a plurality of nodes generating and using Operation Administration and Maintenance, OAM, detection frames for link fault detection and a plurality of nodes transparent forwarding the OAM detection frames used for link fault detection, characterized in that the control method comprises: a first node generating and using OAM detection frames for link fault detection interacting with a second node generating and using OAM detection frames for link fault detection by the OAM detection frames to detect link connectivity, wherein there is at least one node transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node, and there is no other node generating and using OAM detection frames for link fault detection between the first node and the second node; when the first node and the second node detect a link fault by not receiving the OAM detection frame, blocking a port of the first node and a port of the second node, wherein both of the two ports are connected to two ends of a link with the detected link fault respectively, and wherein the detected link fault occurs on at least one of the following link: a) a link between the first node and the node transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node, b) a link between the second node and the node transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node, and c) a link between two nodes transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node; and the first node and the second node sending link fault alarm protocol frames respectively to other nodes generating and using OAM detection frames for link fault detection in the Ethernet ring network, to notify a master node to perform protection switchover, wherein the master node belongs to a ring protection link and is selected from the nodes generating and using OAM detection frames for link fault detection except for the first node and the second node. a first node generating and using OAM detection frames for link fault detection interacting with a second node generating and using OAM detection frames for link fault detection by the OAM detection frames to detect link connectivity, wherein there is at least one node transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node, and there is no other node generating and using OAM detection frames for link fault detection between the first node and the second node; when the first node and the second node detect a link fault by not receiving the OAM detection frame, blocking a port of the first node and a port of the second node, wherein both of the two ports are connected to two ends of a link with the detected link fault respectively, and wherein the detected link fault occurs on at least one of the following link: a) a link between the first node and the node transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node, b) a link between the second node and the node transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node, and c) a link between two nodes transparent forwarding the OAM detection frames used for link fault detection between the first node and the second node; and the first node and the second node sending link fault alarm protocol frames respectively to other nodes generating and using OAM detection frames for link fault detection in the Ethernet ring network, to notify a master node to perform protection switchover, wherein the master node belongs to a ring protection link and is selected from the nodes generating and using OAM detection frames for link fault detection except for the first node and the second node.