This application provides an example delay measurement method and an example network device. The method includes receiving, by a first network device, a first service flow. The method also includes determining, by the first network device, a first delay value based on a first measurement code block in the first service flow. The first delay value is a time difference between a first moment at which the first measurement code block is detected in the first network device and a second moment at which the first measurement code block is detected in the first network device.