Abstract: At present, prefecture-level companies use a base allocation model to allocate investment to county-level power supply units. This model lacks effective consideration of actual power grid demand and investment capacity, resulting in overdue project schedules and insufficient investment benefits during investment implementation. Therefore, this paper uses the analytic hierarchy process to construct an annual investment scale estimation model driven by investment capacity and investment demand. It establishes a hierarchical structure covering five dimensions, including the external policy environment, project management level, and current power grid operation status. Based on the actual characteristics and demands of each county-level power supply unit, the model quantitatively calculates the annual investment scale. A case study verifies that the model can accurately direct investment toward regions with strong capacity and urgent demand. The results provide replicable theoretical support for power grid enterprises to improve investment benefits and lean management and demonstrate strong potential for wider application.