OAM switching method and network device

The invention provides an OAM switching method applied to a network device. A first OAM example is installed on a first line card in the network device, a second OAM example runs on a second line card, the second line card sends a first OAM message according to an OAM parameter, and the first line card enables to send the OAM message. The first line card judges whether a heartbeat message sent by the second line card in the network device is received, and if the first line card does not receive the heartbeat message sent by the second line card, the first line card sends a second OAM message according to the OAM parameter. As the line card cannot send the heartbeat message in the case of a fault, the first line card can detect the fault of the second line card and send the OAM message to the link detected by the second OAM example, therefore the link switching caused by the fault of the line card can be avoided when the network device can communicate with the located link thereof. 种OAM切换方法，应用于网络设备。网络设备中的第线卡安装