There is a contradiction between the rapid growth of data flow and the real-time control of information in a smart substation. Therefore a new 2 layer Ethernet technology based on a time-sensitive network is proposed to schedule the traffic. This technology adopts ‘slot windows monopoly’ and ‘sharing thoughts’ in transmission time, a frame preemption mechanism in the transmission channel, and classification according to the flow characteristic at the front end. It also optimizes the configuration of parameters through an algorithm at the back end. Thus this technology can improve the flow scheduling mechanism of the process layer to the traditional switch in the smart substation, and can promote the effect of deterministic delay scheduling for time-sensitive traffic. It thus provides the transmission service with low delay jitter for the ethernet network of a smart substation, and puts forward a new idea for improving Quality of Service (QoS) of a power system. This work is supported by the Science and Technology Project of the Headquarters of State Grid Corporation of China “Research on Key Technologies of FlexE Flexible Ethernet Technology Applied in Energy Internet” (No. SGZJDK00DYJS2000030).