Abstract: With gradually deepen of electric power system reform and harsh situation of power grid business in China, importance of grid investment economic benefit evaluation is constantly improving in grid business. Due to unclear benefit issues derived from three fundamental characteristics, namely power grid network characteristics, continuous yearly investment and semi non-profit requirement, economic analysis and evaluation of complex system of main network projects in network structure have not been solved well. Based on physical characteristics of regional power transmission project, impacts of new construction on power grid safety, reliability and economy are analyzed. Set of physical indexes is built first. Then deep, direct and indirect physical benefit indicators are extracted based on intuitionistic fuzzy sets method and interpretive structure model. Economic mapping of core physical architecture is proposed according to grid investment significance. Through economic mapping of core physical architecture, definition of economic benefits of regional power transmission projects area can be further clarified.