This application provides an optical link fault identification method, and relate to the field of communications technologies. The method includes: obtaining performance data of a network device, extracting a feature parameter of the performance data, and identifying a fault mode on an optical link based on the feature parameter. The method resolves problems of a difficulty in fault identification and slow troubleshooting that are caused by a large quantity of devices, many line faults, and a difficulty in obtaining manual troubleshooting cases. In addition, a fault can be quickly identified when the fault occurs, improving troubleshooting efficiency. When an optical link risk does not cause a fault, deterioration of the performance data can be found in advance based on a feature, to perform identification and warning.