Abstract: The construction phase of large-scale infrastructure projects exhibits significant load fluctuations and strong time-varying characteristics, making it difficult for traditional static capacity configuration methods to balance safety and economy. To address the coexisting issues of capacity redundancy and power supply insufficiency, this paper develops a dynamic capacity optimization model based on the load characteristics throughout the entire construction cycle. The model is validated through simulations of a metro tunnel construction section, forming a construction rhythm-adaptive capacity configuration strategy. Results demonstrate that the proposed method significantly improves load matching, power supply reliability, and energy consumption performance, providing effective technical support for the refined design and intelligent management of temporary power supply systems.