In order to meet the needs of real-time dynamic parameter identification of massive line measurement data in power grid, a method of identifying software to obtain real-time measured data of line dynamically for dynamic parameters is proposed. The mathematical expression of transmission line parameter identification based on SCADA measurement is deduced by using transmission line model, and a line parameter identification model is established. Design identification software and EMS system data forwarding interface, as well as the line modeling program. The application of dynamic parameter identification in Yuncheng Power Grid in Shandong Province shows that the proposed method can effectively improve the accuracy of the line parameters and improve the passing rate of state power grid evaluation of Yuncheng with a high popularization and application value.