Abstract: With the intelligent development of the power grid,especially the promotion of high-definition video services,network link congestion occurs at the end nodes of the data communication network,such as in substations of all levels,which will lead to the failure of the operation and maintenance personnel in the station to report the daily operation information in serious cases. Under the condition that the bandwidth cannot be improved in a short time,the quality of service（QoS） strategy is successfully deployed in Yuncheng and Furui substations,two 500 kV stations with obviously insufficient bandwidth in the current network environment,and the operation parameters of various services before and after QoS policies deployed are also recorded. Practice has proved that after the deployment of QoS strategy,the important service packet loss rate,delay and other parameters of bandwidth congested stations have been improved to a certain extent.