Data centers consume about 2% of the world’s electricity with continuing growth. The power supply system plays a significant role in the energy saving and decarbonization of data centers. The development of power electronics brings opportunities for more efficient and reliable data centers. This article presents an overview of the data center power supply system covering the power delivery path from the grid edge to onboard point-of-load (PoL) conversion. The system architectures are introduced at first with the discussion on efficiency and reliably. The power conversion stages of data center power supply system are discussed as ac–dc conversions and dc–dc conversions. The state-of-the-art techniques in topology, control, and device are investigated. This article is an attempt to provide an overview for high-performance data center power supply system design.