Abstract: After the modern infrastructure system policy was put forward, new requirements were put forward for the construction of transportation, water conservancy, energy, and new infrastructure represented by information and communications. Starting from the effectiveness of infrastructure, various industries have proposed optimization directions for layout, structure, function, and system integration. This article starts from the study of the functional role of the modern infrastructure system, analyzes the important role of the power grid infrastructure in the modern infrastructure system, and uses Pearson's correlation coefficient to study the relationship between the power grid infrastructure line length and transformer capacity scale and the electricity consumption of the whole society. The article also forecasts the length of transmission lines and transformer capacity scale in the eastern, central, western, northeastern, and other regions in 2025 and 2035. On this basis, the layout, structure, and function of the power grid infrastructure within the framework of the modern infrastructure system are analyzed, and the logic of system integration optimization is given. In addition, the requirements for power grid layout structure function and system integration optimization in building a modern infrastructure system are put forward, providing a reference for the investment and construction of power grid infrastructure.