Fault detection method and device

The embodiment of the invention provides a fault detection method and device, relates to the technical field of communication, and is used for improving the efficiency of fault detection in a fault ring network. The fault detection method is applied to a ring network comprising a plurality of nodes, the plurality of nodes comprise a master node and at least one slave node, the master node comprises a first port and a second port, and the method comprises the following steps: the master node sends a first service message through the first port; when the main node does not receive the first service message through the second port, the main node sends a fault detection message through the first port; when the fault detection message reaches the ith slave node, the hop count of the fault detection message is i, i is an integer, i is greater than or equal to 1 and less than or equal to M, and M is the number of a plurality of nodes included in the ring network; and if the main node does not receive the response information of the fault detection message, the main node determines the position of the fault node in the ring network according to i.