Abstract: Considering the safety and stability level of power grid, energy supply and energy saving and emission reduction, a method of efficiency analysis of UHV network is presented. In the aspect of safety and stability of power grid, this paper analyzes the level of short-circuit current of UHV network, the influence of the power flow distribution and the safety margin of the line. In the aspect of energy supply, the paper analyzes the effect of UHV electricity on the balance of power supply and demand. In the aspect of energy saving and emission reduction, this paper analyzes the UHV network how to economize the standard coal, reduce carbon dioxide, sulfur dioxide and NOx emission. The application in Tianjin power grid is analyzed. The research shows that this method can analyze the efficiency of UHV network in omni-directional and multi-angle, and it has important guiding significance for enhancing the foresight, scientificity and rationality of power grid planning scheme and improving the safety and stability of power grid operation.